The DSI ES440-B1-C9 is part of the ES440 series by Designed Security, Inc. (DSI). These button control devices are used in access control applications such as emergency exits, lock release, and request to exit scenarios. 

• Functionality: The ES440 units are complementary to most access control systems and can be used as a stand-alone device.
• Face Plates: Comes with “PUSH TO EXIT” faceplate.
• ES440: Fits a single gang electrical box.
• ES440: 3.80”w x 4.60”h x 2.00”d