APM Illuminator for Crosshair Eyepieces

I purchased this reticle illuminator alongside the APM 24mm 55º reticle eyepiece for alignment of telescopes. It works, but does require a bit of finagling. The switch doesn't always turn on or off and sometimes the brightness doesn't adjust up or down. I found the only way to guarantee it stays turned off is to slightly unscrew the battery compartment.

As always, shopping with David Astro is pleasant, items arrive quick and well packaged. I'll be returning in the future.