Features: This item has new two-way large power silicon controlled rectifier and the current can be up to 40A, which is a good solution to over-current of electric stove wire caused by low resistance during cooling. It can easily adjust the output voltage on a scale of 0-100% (nonlinear) to power electric device. Designed with large and thick heat sink that would enhance heat dissipation. This voltage regulator is adjusted with button which is much more stable than potentiometer. Voltage regulator has wave voltage absorbing circuit and effective protects large power silicon controlled rectifier, longer service life and more durable. It can be used as power supply for large electrical devices, enough for household appliances or for small factory. Could be widely used as heat controller on electric stoves, water heaters, light dimmer on lamps, speed controller on small motors, or temperature controller on electric soldering iron, etc. Specification: Voltage: AC 220V Max Power: 4000W (instantaneous limit power for resistive load; for long time use, 2000W or lower is recommended) Voltage Adjustment: 0-100% (nonlinear) Panel Size: 7.5*6*2cm / 3*2.4*0.8in Voltage Controller Size: 8.5*6*4cm / 3.3*2.4*1.6in Weight: 152g / 5.4oz (approx.) Package list: 1 * Voltage Controller 1 * ABS Panel 1 * Panel Sticker 1 * Cable Note: It can not replace electric bicycles' battery charger, nor drive electric appliances which use switch power supply (such as 110V TV, speaker, refrigerator, air conditioner, rice cooker with a computer), and cannot drive induction cooker, energy saving lamp. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.