Belimo LF24-SR US Damper Actuator, 35 in-lb [4 Nm], Spring return, AC/DC 24 V, 2...10 V, modulating. The LF series actuators provide true spring return operation for reliable fail-safe application and positive close-off on air tight dampers. The spring return system provides consistent torque to the damper with, and without, power applied to the actuator.
