Our closer is engineered for doors up to 150lbs, with Fixed Size #3 Power. MATERIAL: Compare to Grade 2 Door Closers – UL 3 Hour Fire Rated, Surface Mounted and crafted from durable Aluminum. This closer is adjustable and boasts a precise cast aluminum body, forged steel arm and heat-treated piston for smooth operation that can support doors weighing up to 150 lbs.