Hansens ultra-quiet spring return damper actuator is ideal for the HVAC market. Featuring the patented Whisper Motion TM air brake and the always reliable Synchron AC synchronous motor, our actuator design eliminates the wind-up noise that often occurs when the motor and gear train start spinning at more than ten times their normal operating speed. In fact, compared to Hansen, the other actuators on the market today generate five times the sound energy during the spring return cycle, resulting in the unwanted wind-up noise. Wind up noise is reduced to whisper quiet levels due to our patented air brake technology.