Accurate crossing detection triggering designed to achieve precise control. Optocouplers isolate strong and weak electricity for more reliability operating. Comes with time and current adjustment knob, turn left to decrease the value and right to increase it. LCD digital screen displays current set time and current. Time 1-50 cycles, 20 milliseconds per cycle, current 30-99%. If there is a sudden power outage or shutdown during the welding process, the welding parameters be automatically saved. After startups, it can be used directly without the need for re debugging. The power cord and cable rack adopt screwless quick connection terminals for more convenient operating Current:40A Size:.6x4cm/2.36x1.57inch Colour:As Shown Material:PCB Package Contents: 1 * Control Board Only the above package content, other products are not included. Note: Light reflection 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.