Camden Door Controls CM-40/41 Series all-active switches are heavy-duty, ADA-compliant door controls. The 4 1/2” round faceplates are stainless steel or solid brass, and the assembly is designed for easy installation.  The CM-40 and CM-41 switches mount to standard 2 x 4 electrical boxes. The SPDT (and optional DPDT) switches are UL/CSA approved, and rated 15 amps @ 30 VDC. The 4 1/2” square stainless steel backplate on the CM-41 is large enough to dress-up (cover) a poorly installed electrical box. It will also fit perfectly on most 4 1/2” surface boxes.