cctv lens extension ring (MOQ-200)

M12 Extension Rings, made of blackening aluminum materials, is placed between the M12 small lens and the lens holder, to fix the lens tightly in a precise position when it has reached the suitable Back Focal Length and the camera has reach the clear image. So, this M12 extension rings is to help adjust the focusing of the lens and fix this place.

Compared to other methods, such as using M12 Springs, glue or plastic M12 rings, the aluminum ring can help the lens fix the lens more tightly and keep the lens in the precise optical axis centre when work in a rough environment.