1Adopt high power SCR as the internal chip. 2Thickening metal shell, high temperature resistant and durable in use. 3Achieve stepless voltage adjustment by knob. 4Zero hysteresis, zero delay, fast response. 5The shell is equipped with a universal multi-purpose socket and a power indicator.Features:Adopt high power SCR as the internal chip. Thickening metal shell, high temperature resistant and durable in use. Achieve stepless voltage adjustment by knob. Zero hysteresis, zero delay, fast response. The shell is equipped with a universal multi-purpose socket and a power indicator. Effectively protect high-power thyristor against surge, anti-spike, RC absorption of multiple protection. Specification: Model: BTA-4000WInput voltage: AC220V Plug type: CN plug(3 pins) Output voltage: 0-220V stepless adjustable (the voltmeter does not work when output voltage is lower than 5V) Maximum power: 4000W (fit for 2000W-3000W resistive load) Rated current: 9A Limit current: 18A Package weight: Approx. 507g Package List:1 x SCR Voltage Regulator Note: 1. Please kindly make a note if you need any plug adapter.