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Sales & Clearance

Astronomy sales at David Astro, current markdowns across the catalogue, including open-box units, discontinued models still fully supported, and overstock we would rather see on a telescope than on a shelf. Everything here is held in Canadian stock and carries the same warranty and support as full-price inventory.

Reduced price does not mean reduced service. We will still calculate your back-focus, confirm compatibility and support the item after the sale, exactly as we would for anything else in the catalogue.

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO M42 Plate for CAA Rotator

Converts ZWO CAA Rotator to M42 T-Threads Maintains 55mm Backfocus Standard CAA with M42 Plate Stays at 16.5mm Ideal for ASI533, ASI2600, and Othe...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00

ZWO M42-M48 Adapter - 16.5mm

Adds a precise 16.5mm of optical path length Connects male M42 (T2) threads to female M48 threads Essential for achieving standard 55mm back focus...

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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00
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Original price CA$35.00
Original price CA$35.00 - Original price CA$35.00
Original price CA$35.00
Current price CA$32.00
CA$32.00 - CA$32.00
Current price CA$32.00

ZWO M42e to M48i Extension - 22.5mm

Establishes precise 55mm back focus with specific ZWO camera/filter wheel combinations Provides exactly 22.5 mm of optical path length Connects M4...

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Original price CA$35.00
Original price CA$35.00 - Original price CA$35.00
Original price CA$35.00
Current price CA$32.00
CA$32.00 - CA$32.00
Current price CA$32.00
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Original price CA$32.00
Original price CA$32.00 - Original price CA$32.00
Original price CA$32.00
Current price CA$29.00
CA$29.00 - CA$29.00
Current price CA$29.00

ZWO M48 Extension - 16.5mm

Adds exactly 16.5 mm of spacing to an M48 imaging train M48x0.75 male and female threads Wide 43.2 mm clear aperture prevents vignetting with full...

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Original price CA$32.00
Original price CA$32.00 - Original price CA$32.00
Original price CA$32.00
Current price CA$29.00
CA$29.00 - CA$29.00
Current price CA$29.00
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Original price CA$17.00
Original price CA$17.00 - Original price CA$17.00
Original price CA$17.00
Current price CA$15.00
CA$15.00 - CA$15.00
Current price CA$15.00

ZWO M48-M42 Adapter

Converts female M48x0.75 threads to female M42x0.75 T-threads Adds 0mm of optical path length to the imaging train Durable black anodized aluminum...

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Original price CA$17.00
Original price CA$17.00 - Original price CA$17.00
Original price CA$17.00
Current price CA$15.00
CA$15.00 - CA$15.00
Current price CA$15.00
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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO M54 Adapter replacing EFW

Replaces the ZWO EFW to achieve 55mm back focus with the OAG-L Adds only 15 mm of optical length to the imaging train Holds a single 2-inch mounte...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00

ZWO M54 Extension - 16.5mm

Optical Length: 16.5mm Connection Side 1: M54x0.75 Male Thread Connection Side 2: M54x0.75 Female Thread Material: Anodized Aluminum Descriptio...

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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00
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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00

ZWO M54 Extension - 21mm

Adds precisely 21mm of optical path length M54x0.75 male and female threads for secure connections Prevents vignetting with full-frame sensors Mac...

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Original price CA$25.00
Original price CA$25.00 - Original price CA$25.00
Original price CA$25.00
Current price CA$22.00
CA$22.00 - CA$22.00
Current price CA$22.00
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Original price CA$35.00
Original price CA$35.00 - Original price CA$35.00
Original price CA$35.00
Current price CA$32.00
CA$32.00 - CA$32.00
Current price CA$32.00

ZWO M54(M)-M48(F) Adapter - 21mm

Adds exactly 21mm of optical path length Connects M54 male threads to M48 female threads Standard 2-inch filter threading on the M48 side Black an...

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Original price CA$35.00
Original price CA$35.00 - Original price CA$35.00
Original price CA$35.00
Current price CA$32.00
CA$32.00 - CA$32.00
Current price CA$32.00
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Original price CA$17.00
Original price CA$17.00 - Original price CA$17.00
Original price CA$17.00
Current price CA$15.00
CA$15.00 - CA$15.00
Current price CA$15.00

ZWO M54-M48 Adapter

M54 male threads on one side, M48 female threads on the other Zero-profile design preserves critical back focus Converts larger M54 ports to the c...

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Original price CA$17.00
Original price CA$17.00 - Original price CA$17.00
Original price CA$17.00
Current price CA$15.00
CA$15.00 - CA$15.00
Current price CA$15.00
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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO M68 Sensor Tilt Plate

Corrects sensor tilt for sharp, round stars across the entire frame Adds a minimal 5 mm of optical path length to the imaging train Connects the Z...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$517.00 - Original price CA$979.00
Original price CA$517.00
CA$465.00 - CA$881.00
CA$465.00 - CA$881.00
Current price CA$465.00

ZWO Narrowband Filter Set - 7nm H-alpha, OIII & SII

Includes H-alpha, OIII, and SII filters (1.25" or 2" mounted, 36mm unmounted) 7nm bandpass for high-contrast imaging Ideal for creating "Hubble Pa...

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Original price CA$517.00 - Original price CA$979.00
Original price CA$517.00
CA$465.00 - CA$881.00
CA$465.00 - CA$881.00
Current price CA$465.00
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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00

ZWO Narrowband H-alpha Filter - 7nm

Isolates Hydrogen-Alpha light at a 7nm bandpass 1.25" or 2" threaded cell, or 36mm unmounted Blocks light pollution and moonlight for extreme cont...

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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00
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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00

ZWO Narrowband OIII Filter - 7nm

7nm Bandpass at OIII Emission Line Isolates Planetary Nebulae and Supernova Remnants 1.25" or 2" Threaded Cell, or 36mm Unmounted 1/4 Wave Optical...

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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00
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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00

ZWO Narrowband SII Filter - 7nm

Isolates the 672nm Sulfur-II emission line 7nm bandpass for high-contrast imaging 1.25" or 2" threaded cell, or 36mm unmounted 1/4 wave polished o...

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Original price CA$181.00 - Original price CA$349.00
Original price CA$181.00
CA$162.00 - CA$314.00
CA$162.00 - CA$314.00
Current price CA$162.00
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Original price CA$83.00
Original price CA$83.00 - Original price CA$83.00
Original price CA$83.00
Current price CA$74.00
CA$74.00 - CA$74.00
Current price CA$74.00

ZWO Nikon Lens Adapter for EFW

Connects Nikon F-mount lenses to ZWO Electronic Filter Wheels Engineered for cameras with 6.5mm back focus Provides 20 mm of spacing Standard M42x...

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Original price CA$83.00
Original price CA$83.00 - Original price CA$83.00
Original price CA$83.00
Current price CA$74.00
CA$74.00 - CA$74.00
Current price CA$74.00
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Original price CA$97.00
Original price CA$97.00 - Original price CA$97.00
Original price CA$97.00
Current price CA$87.00
CA$87.00 - CA$87.00
Current price CA$87.00

ZWO Nikon-T2 Adapter

Attaches Nikon F-mount lenses to ZWO cameras Standard M42x0.75 T-thread camera interface 29mm main body length for 17.5mm back-focus cameras Inclu...

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Original price CA$97.00
Original price CA$97.00 - Original price CA$97.00
Original price CA$97.00
Current price CA$87.00
CA$87.00 - CA$87.00
Current price CA$87.00
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Original price CA$179.00
Original price CA$179.00 - Original price CA$179.00
Original price CA$179.00
Current price CA$161.00
CA$161.00 - CA$161.00
Current price CA$161.00

ZWO OAG

Eliminates Differential Flexure Reduces Overall System Weight Includes 1.25" Guide Camera Holder M48 and M48 to M42 Adapters Included Spacer and H...

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Original price CA$179.00
Original price CA$179.00 - Original price CA$179.00
Original price CA$179.00
Current price CA$161.00
CA$161.00 - CA$161.00
Current price CA$161.00
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Original price CA$279.00
Original price CA$279.00 - Original price CA$279.00
Original price CA$279.00
Current price CA$251.00
CA$251.00 - CA$251.00
Current price CA$251.00

ZWO OAG-L

Large 12mm x 12mm prism for brighter guide stars M68, M54, and M48 connection options 17.5mm thickness preserves 55mm backfocus Designed for ZWO A...

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Original price CA$279.00
Original price CA$279.00 - Original price CA$279.00
Original price CA$279.00
Current price CA$251.00
CA$251.00 - CA$251.00
Current price CA$251.00
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Original price CA$21.00
Original price CA$21.00 - Original price CA$21.00
Original price CA$21.00
Current price CA$20.00
CA$20.00 - CA$20.00
Current price CA$20.00

ZWO Replacement Fan for ASI Cameras

Official ZWO OEM replacement fan Restores original cooling performance to Cooled/Pro cameras Backed by a 2-year manufacturer warranty Descripti...

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Original price CA$21.00
Original price CA$21.00 - Original price CA$21.00
Original price CA$21.00
Current price CA$20.00
CA$20.00 - CA$20.00
Current price CA$20.00
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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO Sensor Tilt Plate - M42

Corrects sensor tilt for flat fields and sharp stars edge-to-edge Adds only 5mm of thickness to the optical path Suitable for APS-C cameras like t...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO Sensor Tilt Plate - M48

Corrects Sensor Tilt: Ensures sharp stars across the entire image field by squaring the camera sensor to the optical axis. 5 mm Optical Path Lengt...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00

ZWO Sensor Tilt Plate - M54

Corrects sensor tilt for ZWO ASI6200, 2600, and 2400 cameras Connects compatible cameras and the M68 OAG to a 2" EFW Adds a minimal 5mm of optical...

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Original price CA$41.00
Original price CA$41.00 - Original price CA$41.00
Original price CA$41.00
Current price CA$36.00
CA$36.00 - CA$36.00
Current price CA$36.00
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Original price CA$27.00
Original price CA$27.00 - Original price CA$27.00
Original price CA$27.00
Current price CA$24.00
CA$24.00 - CA$24.00
Current price CA$24.00

ZWO Soft Bag for Cooled Cameras

Official ZWO Soft Bag for ZWO Cooled Cameras Constructed from Padded Heavy-Duty Fabric Lightweight Alternative to Hard Cases Description FAQ Sp...

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Original price CA$27.00
Original price CA$27.00 - Original price CA$27.00
Original price CA$27.00
Current price CA$24.00
CA$24.00 - CA$24.00
Current price CA$24.00
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What Goes on Sale and Why

Understanding why an item is discounted helps you judge whether it is the right purchase, so we are explicit about the reason wherever we can be.

  • Open-box and display units: Returned or demonstrated equipment that has been inspected and tested here, typically indistinguishable from new in use.
  • Superseded models: Products replaced by a newer revision, often with only minor changes and full parts and warranty support remaining.
  • Overstock: Items we hold more of than current demand justifies, discounted while the stock lasts.
  • Seasonal accessories: Dew control, cases and cold-weather items that move seasonally and are reduced outside their peak.
  • End-of-line accessories: Adapters, rings and small parts from lines being retired, which remain perfectly serviceable.
  • Used equipment: Our separate collection of tested second-hand gear, for buyers comfortable with pre-owned optics and mounts.

Why Choose David Astro for Discounted Astronomy Gear

A discount is only a good deal if the item is right for your setup and stays supported afterwards.

  • Compatibility checked before you commit: We will confirm a sale item actually fits your telescope or mount, because a bargain adapter that does not fit is not a bargain.
  • Condition stated honestly: Open-box and display items are described as what they are, with any cosmetic marks noted.
  • Full warranty on new items: Discounted new stock carries the same manufacturer warranty as anything else we sell, handled domestically.
  • Same support after the sale: Setup help, spacing calculations and in-house diagnostics apply to discounted purchases too.

Astronomy Sales in Canada: Frequently Asked Questions

Do sale items carry a warranty?

New discounted items carry the full manufacturer warranty. Open-box items are covered as stated on the listing, and we handle any claim domestically rather than routing it internationally.

Is an open-box item risky?

Not in our experience. Everything is inspected and functionally tested here before it is relisted, and anything with a cosmetic mark is described. Optics are checked for coating condition and collimation.

Can I still get support on a discontinued model?

Generally yes. We stock spare parts and adapters for many superseded models, and we say on the listing where parts availability is limited.

How long do sale prices last?

Until the stock is gone. These are finite quantities rather than a recurring promotion, so an item that disappears from this collection has usually sold rather than returned to full price.

Found something here?

Ask us before you order and we will confirm it fits your setup. Canadian stock, full support.