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 Drive Plate Polishing Machine Dayi *General Control Panel Size 5.2*6.2CM*Brushless sensorless angle grinder drive control board general*Control board drive voltage: 18V (5 strings of lithium batteries, fully charged 21V), power 300W.*The battery pack marked with 48V, 68V, 88V, 98V, 128VF or TV can be used, 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 must first connect the wire---fix the motor---install the case---tighten the screw---make sure that the square shaft of the head can be easily rotated without jamming---connect the power supply--- Press down the speed control switch so that there is no gap in the shell! Otherwise, there may be a buzzing alarm!*To prevent damage to the motherboard, please follow the requirements.Package Contents:1*Control boardNote: The real color 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.