Features:* The product is suitable for Dayi 2106/161/169 brushless electric wrenches. Has been tested before sale 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 of Lithium Batteries, 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 of 2 parallel 10 cells or 5 series of 3 parallel 15 lithium batteries, fully charged 21V) .* Before testing the machine, you first need to connect the wire --- fix the motor --- install the housing --- tighten the screw --- make sure the square head shaft can be rotated easily without jamming --- connect the power supply --- press the switch speed control so that there is no gap in the coating! Otherwise, a buzzing alarm may occur!* To prevent damage to the motherboard, please follow the requirements. Package Contents: 1 * Control Board 1 * Switch Note: 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.