For lenses with a 72mm thread. Screws onto the lens with a fluid action thanks to the sturdy construction and aluminum screw thread. The adapter ring is crucial to the LEE Filters system. It screws onto the camera’s lens and, in turn, the filter holder clips onto the adapter ring. The standard adapter ring is suitable for use with lenses up to a moderate wide angle. It sits in front of the lens’s front thread. The standard adapter ring is compatible with all lens focal lengths from approximately 24-28mm (35mm SLR equivalent) and upwards.