Stanley Hardware 74-5750 Pneumatic Door Closers Standard Duty Shock Absorbing Door Closer Torsion Bar And Large Air Controlled 1-1/2 Inch Tube Combine To Provide Twice The Latching Power Of A Standard Duty Closer Fully Adjustable Door Closing Speed And Permanently Lubricated To Extend Operating Life Clear coated Aluminum For screen, storm or combination doors Pneumatic operation with non-collapsing, full-floating leather piston Spring minimizes shockloads applied to door and closer by heavy winds and abuse