The Lee Seven 5 Filter Holder is for use with compact system cameras & designed to hold two Seven 5 75x 90mm filters. The holder screws in to the lens via a screw-in adapter ring (not included, available separately). Simply select the correct adaptor ring for your lens, screw it onto the end of the lens, clip the holder onto the adapter ring & drop in the appropriate filter. Check your lens to determine what thread size adpater ring you need.