The Cokin P-Series Filter Holder is part of the Cokin modular filter system The P-Series holder can accommodate up to x 3 of the 83 mm P-Series filters. Select an adapter ring to fit the diameter of your camera lens, lock it into the holder, attach the combination to the lens & add a desired P-Series filter. The holder has the rear facing adapter ring slot plus 2 forward facing slots for rectangular filers & one narrow slot for a rotational round filter, such as a polariser. The holder may be rotated for alignment of specific filter effects. One set of filters may be used on many different lenses, with the proper adapter ring, thus cutting down on the number of different size filters that must be carried. P size adapter rings are available in the following sizes: 48/49/52/55/58/62/67/72/77/82mm Please Note: P-Series Filter Holder is the item highlighted in the image above.