Skip to content
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Dew-Not

Dew-Not

Dew-Not heater strips take a different approach to dew prevention: a flat resistive element distributed across the whole strap rather than a coiled wire, which spreads heat evenly instead of creating hot lines. Even, gentle heating is exactly what you want, because localized heat creates the tube currents that soften an image. David Astro carries Dew-Not products in Canada, held in stock for fast domestic shipping.

Strap length is matched to your optic's circumference. Tell us your telescope, finder and guide scope and we will list the sizes you need.

Filters

$28.00 - $28.00
$28.00
$28.00 - $28.00
$28.00

Dew-Not Heater Strip - .965" Eyepiece

DN001
1 in stock

Fits .965" Eyepieces and 1" Finderscopes Heater Element Length: 3.5" Total Strip Length: 4.5" (11.4cm) Power Requirement: 12V DC, 2.1W Current Dra...

View full details
$28.00 - $28.00
$28.00
$28.00 - $28.00
$28.00
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00

Dew-Not Heater Strip - 10" Scope

DN011

Fits 10" Telescope OTAs 37" Active Heating Element Length 38.0" Total Strip Length 17.8 W Power Consumption at 12V DC Draws 1.49 A Current Integra...

View full details
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00
$65.00 - $65.00
$65.00
$65.00 - $65.00
$65.00

Dew-Not Heater Strip - 11" Scope

DN012
2 in stock

Fits 11" Schmidt-Cassegrain and other large optical tubes Total Strip Length: 40.0 inches (101.6cm) Heating Element Length: 39 inches Power Consum...

View full details
$65.00 - $65.00
$65.00
$65.00 - $65.00
$65.00
$68.00 - $68.00
$68.00
$68.00 - $68.00
$68.00

Dew-Not Heater Strip - 12" Scope

DN013
1 in stock

Fits 12" Telescope OTAs 43.0" (109.2cm) Strip Length 42" Active Heater Element Length Power: 20.2 W at 12V DC Current Draw: 1.68 A Description ...

View full details
$68.00 - $68.00
$68.00
$68.00 - $68.00
$68.00
$70.00 - $70.00
$70.00
$70.00 - $70.00
$70.00

Dew-Not Heater Strip - 14" Scope

DN014
2 in stock

Fits 14" Telescopes and Optical Tubes 49.0" (124.5cm) Total Strip Length 48" Active Thick-Film Heating Element Power Requirement: 12V DC, 23.0 W (...

View full details
$70.00 - $70.00
$70.00
$70.00 - $70.00
$70.00
$77.00 - $77.00
$77.00
$77.00 - $77.00
$77.00

Dew-Not Heater Strip - 16" Scope

DN015

Designed for 16" telescope optical tubes Total Strip Length: 55.0" (139.7cm) Heating Element Length: 54" Power Requirement: 25.8W at 12V DC Curren...

View full details
$77.00 - $77.00
$77.00
$77.00 - $77.00
$77.00
$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00

Dew-Not Heater Strip - 3" Scope

DN004

Fits 3" Telescope OTAs 13.0" (33.0cm) Strip Length 12" Heating Element Length Draws 0.50A at 12V DC (6W) Standard RCA Jack Connector Descriptio...

View full details
$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00
$30.00 - $30.00
$30.00
$30.00 - $30.00
$30.00

Dew-Not Heater Strip - 32mm Guide Scope or 1.25" Eyepiece

DN002
4 in stock

Fits 1.25" Eyepieces and small finderscopes Total Strip Length: 6.5" (16.5cm) Heater Element Length: 5.5" Power Consumption: 3.1W at 12V DC Curren...

View full details
$30.00 - $30.00
$30.00
$30.00 - $30.00
$30.00
$40.00 - $40.00
$40.00
$40.00 - $40.00
$40.00

Dew-Not Heater Strip - 4" Scope

DN005

Length: 15.4" (39 cm) Fits: 4" Telescope OTAs and Dew Shields Power: 7.3 Watts at 12V DC Current Draw: 0.61 Amps Connection: 6' Cord with Mol...

View full details
$40.00 - $40.00
$40.00
$40.00 - $40.00
$40.00
$44.00 - $44.00
$44.00
$44.00 - $44.00
$44.00

Dew-Not Heater Strip - 5" Scope

DN006

Fits: 5" Telescopes Total Strip Length: 16.75" (42.5cm) Heating Element Length: 15.75" Power: 7.9W at 12V DC Current Draw: 0.66A Technology:...

View full details
$44.00 - $44.00
$44.00
$44.00 - $44.00
$44.00
$31.00 - $31.00
$31.00
$31.00 - $31.00
$31.00

Dew-Not Heater Strip - 50mm Guide Scope or 2" Eyepiece

DN003
4 in stock

8" Active Heating Element Length Designed for 2" Eyepieces and 50mm Guide Scopes 4.2W Power Consumption 0.35A Current Draw at 12V DC 9.0" Total St...

View full details
$31.00 - $31.00
$31.00
$31.00 - $31.00
$31.00
$48.00 - $48.00
$48.00
$48.00 - $48.00
$48.00

Dew-Not Heater Strip - 6" Scope

DN007
3 in stock

Total Length: 20.5" (52.1cm) Designed for: 6" Telescopes Power Consumption: 9.6 Watts at 12V DC Current Draw: 0.80 Amps Connection: Long Cord with...

View full details
$48.00 - $48.00
$48.00
$48.00 - $48.00
$48.00
$51.00 - $51.00
$51.00
$51.00 - $51.00
$51.00

Dew-Not Heater Strip - 7" Scope

DN008
4 in stock

Heater Element Length: 24" Total Strip Length: 25.0" (63.5cm) Designed For: 7" Telescope OTAs Power Consumption: 11.8 W at 12V DC Connection:...

View full details
$51.00 - $51.00
$51.00
$51.00 - $51.00
$51.00
$55.00 - $55.00
$55.00
$55.00 - $55.00
$55.00

Dew-Not Heater Strip - 8" Scope

DN009

Fits 8" Schmidt-Cassegrain and similar telescopes 30.0" (76.2cm) strip length with 29" heating element 14 W power consumption at 12V DC Draws 1.18...

View full details
$55.00 - $55.00
$55.00
$55.00 - $55.00
$55.00
$59.00 - $59.00
$59.00
$59.00 - $59.00
$59.00

Dew-Not Heater Strip - 9" Scope

DN010
5 in stock

Fits 9" Schmidt-Cassegrain and other OTAs 33" (83.8cm) Strip Length 32" Active Heater Element Length 15.5W Power Draw at 12V DC Thick-Film Heater ...

View full details
$59.00 - $59.00
$59.00
$59.00 - $59.00
$59.00
$68.00 - $68.00
$68.00
$68.00 - $68.00
$68.00

Dew-Not Heater Strip - Binoviewer

DN017
2 in stock

Dual 6.0" heater strips designed for binoviewers 5" active heating element length per strip Operates on 12V DC power Low 5.6 W total power consump...

View full details
$68.00 - $68.00
$68.00
$68.00 - $68.00
$68.00
$59.00 - $59.00
$59.00
$59.00 - $59.00
$59.00

Dew-Not Heater Strip - Hand Controller

DN016
5 in stock

Total Strip Length: 4.5" (11.4 cm) Heating Element Length: 3.5" Power Consumption: 2.5W at 12V DC Attachment: Dual Rubber Bands Compatibility: Sta...

View full details
$59.00 - $59.00
$59.00
$59.00 - $59.00
$59.00
$32.00 - $32.00
$32.00
$32.00 - $32.00
$32.00

Dew-Not Heater Strip - Rigel Quick Fix

DNRQ

Custom-designed to fit the Rigel QuikFinder Prevents dew formation on finder optics Operates on standard 12V DC power 6-foot cable with a universa...

View full details
$32.00 - $32.00
$32.00
$32.00 - $32.00
$32.00
$43.00 - $43.00
$43.00
$43.00 - $43.00
$43.00

Dew-Not Heater Strip - Telrad Heated Shield

DN018
4 in stock

Custom-fit for Telrad finders Efficient 1.44W power consumption Operates on standard 12V DC power Draws only 0.12 A of current Slides on for easy ...

View full details
$43.00 - $43.00
$43.00
$43.00 - $43.00
$43.00

Even Heating and Why It Matters

A dew heater has to raise the glass a few degrees above the dew point without creating a temperature gradient inside the tube.

  • Flat distributed elements: Heat spread across the strap's whole area rather than concentrated along a wire, which reduces localized hot spots.
  • Length matched to circumference: The strap should encircle the tube near the objective or corrector without excessive overlap, which wastes power.
  • Sizes across the whole rig: Straps for main optics, guide scopes, finders and eyepieces, since each dews independently and often the small ones go first.
  • Standard connectors: RCA connections compatible with common dew controllers, so the straps integrate with whatever controller you use.
  • Controller pairing: Designed to be run through a pulse-width controller rather than at full power, which cuts consumption substantially.
  • Cold-weather durability: Construction intended to remain flexible and intact through repeated freeze cycles.

Why Choose David Astro for Dew-Not

Heater selection is a sizing exercise and a power budgeting exercise, and both are quick to do properly.

  • Sized to actual circumference: We calculate strap length from your tube's outer diameter including a dew shield if the strap sits over it.
  • Whole-rig coverage: We count every optic that dews — main scope, guide scope, finder — so you are not adding straps one at a time across a season.
  • Power totalled: We add the full set's draw to your other loads so your battery lasts the night.
  • Authorized dealer: Genuine products with manufacturer warranty, in Canadian stock.
  • Ships from Canada: No duties or brokerage fees for Canadian orders.

Dew-Not in Canada — Frequently Asked Questions

Why does even heating matter?
Concentrated heat creates convection currents inside the tube that blur detail. A strap that distributes heat evenly at low power keeps the optic clear without degrading the view.
What length strap do I need?
Enough to encircle the tube at the point where it will sit, with a small overlap. Measure the outer diameter and multiply by pi, or tell us the telescope model and we will size it.
Do I need a controller?
Strongly recommended. Running straps at full power wastes battery and risks tube currents. A pulse-width controller holds the optic just above dew point and cuts consumption considerably.
Can I use these on a corrector plate?
Yes, and Schmidt-Cassegrains particularly need them since the corrector sits exposed at the front. Place the strap on the tube just behind the corrector cell.

Sizing heater straps?

Tell us every optic on your rig and we will list the sizes and total the power. Canadian stock, worldwide shipping.