Strong magnets on the back, the marker holder can be attached easily to any metal surfaces, such as refrigerator, whiteboard Widely applicable to whiteboards, refrigerator, locker, cabinet Easy installs, to help keep workspaces neatly organized and easy to find the file Our pen holder organizer is premium, with a strong design on the back, which is strong, sturdy and not easy to break Large opening design makes it easy to place and pick out files, Manufacturer: JAZUAIAO