Bob's Knobs Collimation Knobs for Celestron 11" f/10 with Trifid Fastar

These knobs fit Celestron 11" (28 cm) f/10 SCT versions (metal or carbon fiber tube) with standard thread factory collimation screws and "Trifid" rotary cover Fastar secondary housing. Factory collimation screws are silver Phillips. These knobs will also fit the C11 with Starizona Hyperstar if the collimation screws have standard threads.