It uses great quality ABS, very It will not leave any marks or on the contact surfaces. Great for holding printer paper, notes, photos, posters and cards on whiteboards, fridge, bulletin boards, map,calendars, lockers, file cabinets and other surfaces. Shaped like fly, they’re very easy to handle, to pull off and reposition. With great holding power, they hold items tightly onto the refrigerator or white boards.