Features: *The product is suitable for Dayi 2106/161/169 brushless electric wrenches. It has been tested before selling OK. *It assembly includes motor + control panel + switch (default small switch). *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. Specifications: Product name: Electric wrench brushless motor assembly a set Assembly includes: motor + control panel + switch Motor diameter: 48mm Control Panel Size: 52*62 MM Control board drive voltage: 18V(21V) 300W Gear Size: 7 Teeth Gear diameter: 16mm Color: As the picture show Suitable for: 2106/161/169 brushless electric wrench Quantity: 4PCS Package Contents: 1*Control board 1*Switch 1*Motor 1*Gear Note: 1.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. 2.Please allow slight manual measurement deviation for the data.