Bob's Knobs for Orion Astrograph 4-Vane Phillips Screw Secondary Knobs # CNsec35

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: CNsec35
Fits: Celestron Starhopper, Meade Lightbridge, many GSO, Hardin Optical, and Zhumell models

Secondary Characteristics: 4-vane spider, a deeply recessed center screw, and factory Phillips collimation screws. The secondary plate holding the screws is about 20 mm (3/4") thick.

Knobs: Black plastic, 13 mm (1/2") diameter
Threads: Stainless steel

Notes:
1. The factory collimation screw length, measured below the head, can be either 25 mm or 32-35 mm. Order knobs with the correct screw length for your application. Knobs with 35 mm screws are the most common.