WORKS WITH ANY DOOR AND FLOOR: Door stoppers are suitable for wood, glass, and steel doors. The door stopper wedge works great for kinds of bottom of doors on carpet, concrete,linoleum, tile, stone and wood floors. ENHANCED AND REINFORCED: Door stoppers enhanced hollow design, provides optimum friction to keep the door deadbolt. With a powerful and firm grips, door stopper is perfect for residential, school and office areas as well as industrial, commercial use. DURABLE MATERIAL: These heavy rubber jam with a unique design provides optimum friction to keep the door deadbolt. These door stoppers are made of strong flexible rubber, conducive to environmental protection,flexible, good slip resistance, durable and wear resistance. SIMPLE TO USE: It can be placed underneath the door frame to keep the door at an angle. You don't have to install any door hardware or mechanisms to the baseboards or the wall. Door stops can be stored behind the door, easy to store when not in use and not easy to lose. These door stoppers effectively to keep doors from closing on their own,confrontate strong winds, prevent lock - outs, deter injuries to childrens fingers at home.