Celestron 5 inch (13 cm) f/10 SCT (C5, NexStar 5SE, Omni 127) with black Phillips factory collimation screws. These screws have metric threads.
Note1: These knobs will fit only 2006 and later C5 models that have black Phillips factory collimation screws. All C5 models made prior to 2006 and all post-2006 models with silver factory collimation screws require C5 standard knobs. Check that our screw threads match the factory screw threads before installing.
Note2: 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.