This kit consists of the following filters: CC05M, CC10M, CC20M, CC25M, and CC30M. They are supplied ready-mounted for use in the Lee Filter Holder. This set also contains the Lee Gel Snap. The Gel Snap is Lee's easy and affordable filter holder. Simply insert your 4 x 4" filter, snap it shut, and "snap" it on to any lens 82mm or smaller using the included "Elastomeric Tension Device", also known as an "E.T.D.", i.e, rubber band.