The SIEMENS GND221.1U A.C. 120V Electronic Fire and Smoke Damper Actuator is a metal unit designed for direct mounting in HVAC systems. With a length of 8 inches, height of 2.5 inches, and width of 3 inches, this hard-wired damper actuator is compatible with Siemens products and operates at 120V. Manufactured in the United States, this unit weighs 1 pound and is specifically designed for controlling fire and smoke dampers in industrial and commercial settings.