This voltage regulator adjusted with button whichis much more stable than potentiometer Designed with large and thick heat sink , the speed controller regulator can enhance heat dissipation more effectively Good solution to over-current of electric stove wire caused by low resistance during cooling Using voltage : AC220V , The power : 8000W The speed controller regulator can easily adjust the output voltage on a scale of 0-100 % ( nonlinear ) to power electric device, Manufacturer: Watreketal