Each enclosure is made with a base air foil sometimes referred to as an “arm rest”. However, the air foils are designed to improve air flow, not to be used as an “arm rest.”. If your air foil is acrylic, and breaks, we offer an anodized aluminum retrofit kit to replace the broken air foil. We will need the enclosure model and serial number. We will also need to know if the alarm you are currently using is the FS1645 or FS1650.