XCSOURCE Filter Holder + 77-77 Ring for Lee Tiffen Singh-Ray Cokin Z Series 4X4 4X6 LF405 The Filter Holder fit for all standard 4x4", 4x5.65", 4x5" and 4x6" filter.(such as Lee Hitech Tiffen Singh-Ray Cokin Z Pro etc.) The Holders fit onto the camera lens by snapping on the adapter ring to be screwed onto the lens. Make sure your adapter ring corresponds to your lens diameter. There are screws on the ring to keep the filter set much steady.It can be precisely adjusted and attached to the lens by means of a screw-in adapter ring. A change of camera or of lens necessitates only a change of adapter ring, not the Filter-holder nor the filters. Adapter Ring is Made of Metal and Compatible with Cokin Z series. Adapter Ring Fit filter size: 4x4" 4x5.65" 4x5" 4x6" filter Adapter Ring Filter thread: 77mm (Make sure the adapter ring corresponds to your lens diameter.)