Knobs: Black plastic, 9.5 mm (3/8”) diameter
Threads: Stainless steel
- The factory dust cover will fit properly with Bob’s Knobs installed.
- This secondary has a central screw
The manufacturer Bob's Knobs supplies various collimation screws for Schmidt-Cassegrain, Ritchey-Chrétien and Newton telescopes.
The selection includes screws for primary and secondary mirrors for optics between 5" and 16". In addition, Bob's Knobs offers mounting screws for various mounts from Celestron (CGE, CGE Pro, NexStar), Losmandy (GM-8, G-11) and TeleVue (Gibraltar).
Please refer to the respective specifications and technical data to find the right screws for your model!