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 "Trifid" Fastar secondary housing
Knobs: Black plastic, 9.5 mm (3/8") diameter
Threads: Stainless steel
1. These knobs fit the Celestron 9.25" f/10 SCT with a Fastar secondary, which has black Phillips factory collimation screws that are recessed into the secondary housing. These versions may or may not have EdgeHD optics.
2. Knobs include a set of long spacers so they clear the rotary cover.
3. The factory dust cover will fit normally with Bob's Knobs installed.
4. The rotary secondary cover must remain open when the knobs are installed. The cover is cosmetic only and will not affect operation of the telescope.