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 5" (13 cm) f/10 SCT (C5, NexStar 5) with black Allen, silver Allen, or silver Phillips factory collimation screws. These screws have standard threads. Will not fit scopes with black Phillips factory collimation screws (for that, see Item C5met instead).
Knobs: Black plastic, 13 mm (1/2") diameter
Threads: Black anodized aluminum alloy
1. These knobs will fit all C5 models made prior to 2006, and all 2006 and later models EXCEPT those with black Phillips factory collimation screws. The black Phillips screw model requires C5 metric knobs (Item C5met). Check that our screw threads match the factory screw threads before installing.
2. The factory dust cover will fit normally with Bob's Knobs installed.
3. Some telescope versions have a small plastic cover over the factory collimation screws. This cover must be removed and set aside when Bob's Knobs are installed. The cover is cosmetic only and will not affect operation of the scope.