Flexzion Variable Fan Speed Controller Electronic Vortex Exhaust Control Adjuster 1800w for Inline Duct Fans Mini Blower with Replaceable Fuse Power Cord Built in Metal Mounting Clamp Fuse Protected One control switch for 3 settings: Variable Speed, OFF, and Full Speed Speed control dial to control variable speed: Low, Medium or High speed Built-in a metal clamp at the back of the speed controller; Built-in grounded control outlet Come with 31-1/2" Grounded Power Cord with US standard plug