The OConnor O-Box WM Matte Box has two filter stages that accept either 4 x 4" or 4 x 5.65" filter trays, and the rear stage rotates a full 360 degrees which is useful when working with polarizers or graduated filters. The O-Box deluxe set includes four filter trays, two each of the 4 x 4" and 4 x 5.65" trays, as well as the bellows ring that allows you to mount a 138mm filter as well and stepdown rings for smaller diameter lenses like the Canon EF lenses.