This adapter fits into 2″ focusers and has a male T2 thread on the camera side. So you can adapt nearly any camera via the T2 system. The T2 thread (M-42×0,75 mm) is the connection to bayonet rings to all common SLR cameras.
40mm additional length can make sense: Many telescopes have their focal plane beyond the maximum focuser travel. They are intended for the use of 2″ diagonal and need an extension if a camera is used. The TS FA 240 contains a 40mm extension and so the focus problem can be solved without the need for an additional adapter.
Safety groove The safety groove prevents the accessories from falling out if the locking screw is accidentally slightly loosened. This improves the safety of your equipment.
2″ filter thread On its base, the adapter has a M-48 thread for 2″ filters. So you can use your filters also photographically.