The speed control dial has 3 scales to control shifting: low, medium or high speed. Just use the dial to increase or decrease the fan motor speedOne controller has 3 settings: variable, off and full (on). Safe, practical and easy to useEasily adjust the speed of inline and ducted fans and mini blowersThis speed controller is suitable for fans, routers or motor rheostats AC 120 V 15AUS plug grounded power cord with built-in grounded control socket and rear metal clipPlug Type: US Plug, it applies to Canada, India, Mexico, Thailand, Taiwan, the United States, the Philippines and so on.Colour:As shownMaterial:plasticPackage Contents:1 x Speed ControllerOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.