Knobs for C8 f/10 Secondary with Metric Collimation Screw Threads

Bob's Knobs: Collimate your Schmidt-Cassegrain or Newton-Telescope without tools! It's easy! Just grab a Bob's Knob collimation thumbscrew and turn. You can even do it while looking through the eyepiece on most scopes. And you'll never drop that pesky little Allen wrench or screwdriver into the grass again. Installation is a snap with the included instructions, and you can undo the modification at any time.

Fits: Most Celestron 8” (200 mm) f/10 SCT made in 2005 and later with black Phillips factory collimation screws that have metric threads. Includes SkyWatcher SCT and non-EdgeHD Fastar.