Product Description : Adjustable length adapter lets you attach a T-ring equipped DSLR or SLR camera directly to your telescope Useful for either prime-focus or eyepiece-projection astrophotography with refractors or reflector telescopes Slides into 125 telescope focuser or 2 focuser with step-down adapter has T-threads for attachment of camera body Allows you to vary the magnification without changing the inserted eyepiece when performing eyepiece projection astrophotography Requires T-ring to fit your brand of camera T-rings sold separately