The T2-50,8mm photographic adapter long connects to all cameras and accessories that have a female T2 thread (42x0,75) and it is used to insert everything in the 50.8mm focusers. Compared to the short version, this accessory shift the camera position 40mm to the outside and so it is very useful when the focus point of the telescope is outside too, as it happens in the refractors.
Built entirely of metal and fitted with black anodizing, it presents a clear opening of 38mm (so it does not create any vignetting even with cameras equipped with large sensors, such as DSLRs) and an M48 thread to allow you to connect the filters (such as those against light pollution).