58mm Square Filter Kit for Cokin P Series System. Includes: Graduated Grey ND Square Filter + Square Filter Holder + Adapter Ring + JB Microfiber Lens Cleaning Cloth Includes: 1 x Square Filter Holder / 1 x 58mm Adapter Ring for Cokin P Series / 1 x Graduated Grey Square Filter / JB Microfiber cleaning cloth. Screw the ring adapter onto your lens. Slide the colour filter holder on the ring adapter until it snap in place. The ring material is aluminum. The Square Filter Material is Plastic.