This Binotron 27 SCT Super System is specialized for both SCTs and Refractors. It INCLUDES our new 2" Quartz Mirror 1/10th wave IVB (Interlocking Visual Back) Star Diagonal. This SCT Super System also includes The Binotron 27 Body, The Binoviewer Dual Arm Power Switch for three magnification factors, and The OCS A37. It even includes the Middle Newtonian Spacer Tube if you wajnt to use a Newtonian. The OCS is the A37 which works for a Newtonian but is not the optimized OCS A45 which is best for Newtonians of F5 and faster.