This WonderPana FreeArc Core Unit Kit from FotodioX includes a WonderPana FreeArc Core Unit designed to specifically fit the Nikon AF-S NIKKOR 14-24mm f/2.8G ED lens, as well as a WonderPana 6.6" Holder Bracket. Those items can be combined to allow for the convenient use of two 2.5 to 4.0mm thick filters measuring 6.6" wide, or one 2.5 to 4.0mm thick filter measuring 6.6" wide along with one FotodioX 145mm round filter behind it. A compatible 145mm circular polarizer filter and a 145mm inner-pinch lens cap for 145mm FotodioX round filters are also provided.