The Cokin BX100-OLY is a XL series filter holder specifically engineered to work with the Olympus 7-14mm lens. Due to the optical design of the lens it cannot accept regular style filters because it does not have filter threads on the front of the lens. Cokin created a special 2-piece adapter that fits precisely over the built-in lens hood so that it can accept the included XL series holder.Specs:Material- Filter Holder: Plastic- Filter Holder Adapter Ring: Aluminium alloy- Adapter Ring Lens Collar: Aluminium alloyCompatibility- Filter Holder: Cokin X-Pro Series Filter Holder Adapter Rings- Filter Holder Adapter Ring and Adapter Ring Lens Collar: Olympus M.ZUIKO 7-14mm f/2.8 PRO lens- Filters: (130mm-wide, 3mm-thick) or up to one rectangular (130mm-wide, 3mm-thick) and one round filter made for a Cokin X-Pro Series Filter Holder- Rotating: Yes, 360Whats in the Box:- Cokin X-Pro Series Filter Holder Adapter Kit for Olympus 7-14mm PRO Lens- X-Pro Series Filter Holder- Adapter Ring- Lens Collar