LSDA DC914 Series Surface Door Closer is a commercial closer designed to retrofit the most popular closer door preparation. It includes an adjustable Back Check (BC) feature that allows you to control the opening, as well as the closing speed. Door opening force can be varied by adjusting the power from 1 to 4. This closer is recommended for use on interior and exterior doors with moderate to high traffic. Typical applications include Office Building, Commercial Buildings, and Retail Stores.