This adapter allows RMS thread (.8" x 36 tpi) objectives | Can Also be used if you have a M42 x 1mm to your camera adapter and you can use microscope objectives with movie cameras, DOF systems and other devices. | The cone-shaped adapter is 52 mm in height. | Made of anodized aluminium. | Please Note : the sale is only for the adapter and not the lens. Lens is only shown for pictorial description of the usage of the adapter