Moravian Instruments Long Telescope Adapter with T-thread (M42x0.75)
This long adapter with T-thread is being used with Moravian Instruments G2 cameras.
It provides the correct 55mm back focus that is important especially when used with flatteners. It is compatible with a G2 colour camera or a monochrome camera without internal filter wheel.
If you have a monochrome camera with external filter wheel, you'd need the short version to achieve the correct back focus from a flattener.