VIVOSUN Variable Vent Fan Speed Adjuster Inline Duct Fan Speed Controller One switch for 3 Settings: Variable, Off, and Full Makes it easy to adjust the speed of your inline fans and duct fans Built-in grounded plug for safe operation with all inline fans Voltage/Frequency:120V/60HZ Max. Amperage:15A Included in package: Fan Speed Controller with 32"Grounded Power Cord (US standard plug)