Orion 5117 Prime Focus Camera Adapter for 2-Inch Crayford Focuser Adapter provides a T-thread to allow a camera body to be coupled to a threaded Crayford-type telescope focuser for prime focus photography Attaches to camera T-ring Attaches T-ring equipped DSLR or SLR camera to a threaded Crayford-style telescope focuser Useful for prime-focus astrophotography Requires the appropriate T-ring for your type of camera (sold separately)