This is a 2" manual filter wheel that holds 5 standard 2" filters.
Can be used for visual observations or photography as well.
On the telescope side it has a female M54 thread plus an adapter to convert the M54 thread into M48 thread. An M48 to 2" nosepiece adapter is also included, so if there is no M54 or M48 thread on your telescope, you can still slide it into a standard 2" eyepiece holder barrel of a 2" focuser.

On the camera side it has got a M48 female thread, a M48 to M48 inverter, a large locking ring and a large 2" eyepiece holder barrel (featuring a brass compression ring).
The Filter Wheel is suitable for 2 inch eyepieces and for viewing with single-lens reflex camera and CCD camera (M48 to M42 adapter exclude). Filters can be replaced very quickly, even when the camera is installed or the eyepiece is inserted.