FEATURES : 1. Powerful spring loaded make smooth and controlled closing of door. 2. Mounted on the door externally. 3. Stainless steel enclosed housing and bend resistant hook assure long wear in heavy use. 4. Extra wide hook ensures roller pick up and overcomes alignment problems. 5. Easily replaces any conventional door closer. 6. Perfect complements for ALTOS walk in hinges and latches where self closing doors with controlled closure and needed.