KB Electronics Panel Mount Solid State Variable Speed AC Motor Control 4.0 Max amps # A177-1004 Panel Mount: 1-5/8" Square, 2" length 4.0 Max amps 115 Volts; UL & CSA Approved Not to be used with Capacitor Start or Capacitor Run Motors Applications: Fans, Blowers, Fireplace Blowers, Attic Fans, Humidifiers, Ventilators