The Sharpstar 2.5" 0.8x corrector/reducer for Ritchey-Chretien telescopes is compatible with GSO and other RC telescopes with a focal ratio of f/6 to f/9. Only compatible with 10" - 16" telescopes.
It offers excellent correction across full-frame and illuminates a 44mm image circle. The working distance between the flattener and the sensor is 74mm from the M68 thread.
The reducer includes a removable adapter with an M78 x 1 thread for connection only to Sharpstar's RC focuser. In order to connect it to GSO 3" focusers which have an M77 x 1 thread, you can use our Testar TE-GSO-SHARPSTAR.RED-M68 combo adapter, which allows you to connect both the corrector to the focuser and provides an M68 x 1 thread for connection to common imaging equipment.