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.
Notes:
- These knobs will fit only the Celestron 8” SCT with Fastar secondary and EdgeHD optics. These telescopes are marked “EDGEHD OPTICS” on the corrector ring. Do not use these knobs on the non-EdgeHD Fastar secondary; the screws on these knobs are too long. Be sure to check that the thread length on our knobs matches the thread length on the factory collimation screws.
- Black oxide steel (shown in photo) is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure. Stainless steel provides better corrosion protection in coastal or high humidity areas, or in places where dew or other condensation is common.
