Special Note: The Celestron 9.25â SCT uses either standard 6-32 or metric M3 collimation screws. Allen and set-style factory collimation screws have standard threads. For Phillips collimation screws, most silver screws are standard and most black screws are metric. See our hints for more information.
Collimate your Catadioptric or Newtonian reflector style telescopes 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. These thumbscrews are also much easier to use with gloves on. And perhaps most importantly, 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: Celestron 9.25" (23.5 cm) f/10 SCT versions with standard collimation screw threads (not for CPC 925 or EdgeHD).
Knobs: Black plastic, 16 mm (5/8") diameter
Threads: Black anodized aluminum alloy
1. Silver factory collimation screws have standard threads. Our hints will help you determine which screws are on your telescope. Make sure the knob threads match the factory screw threads before installing the knobs.
2. The factory dust cover will fit normally with Bob's Knobs installed.
3. Knobs include a set of long spacers so they clear the secondary housing lip.
4. Celestron 9.25" SCTs manufactured prior to 2006 have standard collimation screw threads.