Features:* The product is suitable for Dayi 2106/161/169 brushless electric wrenches. It has been tested before selling OK.* 18V 21V brushless angle grinder Dayi disc grinder * Overall control panel size 5.2*6.2CM* Brushless sensorless angle grinder drive control board general* Control board drive voltage: 18V (5 strings lithium battery, Fully charged 21V), power 300W.* You can use the battery marked 48V, 68V, 88V, 98V, 128VF or TV, And its voltage is actually 18V (5 series 2 parallel 10 cells or 5 series 3 parallel 15 lithium batteries, fully charged 21V).* Before testing the machine, you need to connect the wire first--fix the motor--install the housing--tighten the screw--make sure the square shaft of the head can be easily rotated without jamming--connect the power supply--press the speed control switch, so that there is no gap in the shell! Otherwise, a buzzing alarm may occur!* To prevent damage to the motherboard, please follow the requirements. Package Contents:1 * Control Board1 * SwitchNote: The actual colors of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.