Lens extension tube, no sliding, no paint fading The adapter is used to realize the conversion between interfaces Suitable for video and industrial view High grade aluminum, fine workmanship, good When it is used: 1 The camera is port, the lens is C ports, which makes the interfaces into a consistent, but also increases the focal length 2 The camera and lens are both C ports, thus increasing the focal length, Manufacturer: FackLOxc