Honeywell MSTNThe MSTN is a uni directional motor that requires singlepole, double throw switching to drive a damper open and closed. It is compatible with Trol A Temp or Honeywell AOBD dampers. It uses a wafer switch to power the synchronous motor for only 30 seconds while the motor is moving between open and closed. When the motor reaches the open or closed position, the internal switches cut off the power to the motor.