Adapter Camera For Alpha SLR 42mm Mounting Sleeve For Scope : Designed for digital SLR digiscoping connect to observation telescope to shoot comfortably and easily Universal photo sleeve with M42 threads on both ends fits all 42mm diameter glasses so measure the eyepiece to make sure it will fit your specific scope as it is a made unit Adapter T2 : A useful accessory allows you to attach the camera to the Alpha SLR camera to the telescope, camera and other astrophotographic accessories How to use: screw in the adapter adapter , then screw the entire adapter into the DSLR or SLR camera to connect to the telescope or microscope the hollow side of the sleeve does not affect the adjustment of the focusing knob Specification: Material: Aluminum Length: 2.76 inch or 7 cm Total length: 3,11 inches or 7,9 cm Diameter: 1.77 inches or 4.5 cm Thread: both adapters are universal thread M42x0.75 black Mount: for Alpha SLR camera (Compatible DSLR A55, A55, A77, , , A230, A290, A300, , , A390, , A500, , , A700, A850, A900 and most SLR bodies for ) contains: 1 . Adapter camera lens with T ring for Alpha SLR 1 42mm adapter for telescope mounting