Ferum Atlas T54-AL Aluminum Universal Hardware Heavy-Duty Commercial Door Closer, suitable for interior commercial applications. For doors ranging from 121 - 187 lbs. The dual valve separates the controls that can be adjusted at any time, to either of the two closing, or latching speeds. This closer is reversible, allowing for right and left hand operating, and it features an aluminum alloy body with an aluminum finish. This door closer meets ADA requirements, and it has a size 4 spring that accommodates a maximum door weight of 187-Pounds. For a stand and jam application the maximum interior door size is 4'2", and for an exterior door, the maximum door size for a swing out door is 3'8", and for swing in the maximum door size is 3'2". For parallel arm application the maximum interior door size is 3'8", for an exterior door, the maximum door size for a swing out door is 3'2", and for swing in the maximum door size is 2'8". For a perfect installation read the instructions and the measurements included with this door closer.