Tips: Difference between C mount and CS mount lenses: CCTV Lenses are available in two different lens mounts. "C Mount" lens has a flange back distance of 17.526mm vs. 12.5mm for "CS Mount" lens. Because of the shorter back focal distance, CS Mount lens can only be used on CS Mount camera. The camera images will be out of focus if a CS Mount lens is used on a C Mount camera. Many of today's cameras can accept either type of lens, but it is important to be sure that the camera and lens are compatible and set up properly. C Mount lens can be used on CS Mount camera by utilizing a 5mm adapter or adjusting the camera for C Mount lens. Features: *3pcs metal C/CS Mount Lens Converter. *Convert lens C mount to CS mount adapter ring. *Enables C lens to be used on CS mount camera. *Without affecting the installation and use of other accessories. *Easy installation and convenient to use. Specifications: Color: Black Material: Aluminum alloy Standard: Thread 25.4mm / 1in Package Information: Package Size: Approx. 12 * 9 * 3cm / 4.7 * 3.5 * 1.2in Package Weight: Approx. 15g / 0.53oz Package List: 3 * C/CS Mount Adaptor