Ideal for on/off, fail-safe damper control in HVAC systems, this BELIMO spring return actuator can provide true spring return operation for reliable fail-safe application and positive close off on air tight dampers. The spring return system provides a consistent torque to the damper with, and without, power applied to the actuator. Unit provides up to 95° of rotation and has a graduated position indicator displaying 0° to 95°. The actuator may be stalled anywhere in its normal rotation without the need for mechanical end switches. Model is double insulated so an electrical ground connection is not required. Actuator comes with a built-in auxiliary SPDT switch for safety interfacing or signaling (for example, in fan start-ups).