This size 4 door closer from Taymor is made of high-grade steel. It has a high-strength pressure-cast aluminum housing. Two separate speed-regulating valves control its closing and latching speed. Its beautiful narrow design will coordinate with all types of doorframes. For wood, metal or glass and fire exit doors that weight 132 lb to 187 lb. UL and ULC approved. Backed by a 5-year limited warranty.