For the heaviest doors, choose Ideal Security�s pneumatic (air pressure) door closers with torsion bars. Designed for heavy, out-swinging aluminum, steel or wood storm doors over 1-1/2� thick. The door closing speed is adjustable with the air adjusent screw. The tube is aluminum, which will not rust. A speed release washer is included for easy closing when used to hold the door open: A simple push on the door will release the washer and allow the door to close. Easy to install, using the existing holes on your door. If this style of closer was not on your door, new holes may be required. Please follow the instructions. The closer can be installed at the top, middle or bottom of your door, depending on its construction. Brackets and screws for installation are included. Ideal Security supplies storm door hardware to quality door manufactures across North America.