The heavy-duty closer features winter and summer settings for when screens are used instead of glass and features an air bypass for extra latching power. The closing speed is regulated by an adjustment screw at the end of the tube. Tightening the screw will slow or stop the closing, loosening it will speed up the closing. The door closer is for out-swinging storm and screen doors that are from 1-1/4” to 2” thick. All fasteners and brackets are included for a complete and easy installation. This door closer is original equipment quality. Ideal Security supplies storm door hardware to quality door manufactures across North America.