Bob's Knobs for Celestron C5 f/10 Secondary with Metric Collimation Screw Threads # C5metBO

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.

Part: C5metBO
Fits: Celestron 5” (13 cm) f/10 SCT (C5, NexStar 5SE, Omni 127) with black Phillips factory collimation screws. These
screws have metric threads. Will NOT fit scopes with silver factory collimation screws (see Item C5std instead).

Knobs: Black oxide steel, 12 mm (1/2") diameter
Threads: Black oxide steel

Notes:

1. These knobs will fit only 2006 and later C5 models that have black Phillips factory collimation screws (second photo). All C5 models made prior to 2006 and all post-2006 models with black Allen or silver factory collimation screws require C5 standard knobs (See item C5std). Check that our screw threads match the factory screw threads before installing.
2. Some C5 scopes have metric collimation screws that are 10mm long rather than the more common 8mm. If your secondary looks like the third photo above, you have screws with 10mm thread length and you should install knobs without the white spacers.
3. Black oxide steel is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure.
4. The factory dust cover will fit normally with Bob's Knobs installed.
5. 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.