This suitable for 7 pieces of 21700 Battery cells, But this is only a PCB Protection Circuit Board, there is no battery inside. , No Battery Cell !!!!!! This product is component without battery box and core. It is used to repair and assemble batteries pack, only for people who are familiar with battery performance and have practical experience in battery assembly. High compatibility with original device and more durable. Help to repair and assemble batteries pack. Fit Model: For : V11 2020, V11 Absolute Extra, V11 Absolute Extra +, V11 Absolute Extra Pro, V11 Absolute+, V11 Animal, V11 Click-In, V11 Complete Extra, V11 Fluffy Extra, V11 Torque Drive Extra, V11 Torque Size Preparation before assembly: (1). If a core is used, please note:a. 21700 power lithium battery core must be selected,b. A group of 7 cores must be equipped with resistance and capacitance to make their voltage the same. (2). If the old battery is repaired, please test the voltage at both ends of each cell. If the voltage is different, please charge each cell to the same voltage value. Very important: Ensure that the voltage of each cell is the same before welding PCB. Advance notification(Very Important): (1). To use this product, you need to have some professional knowledge and experience. We do not guarantee that you can use it well. (2). You must have 21700 POWER li-ion batteries and the tools such as spot welding machines, soldering irons, multimeters, and suitable chargers, etc. Color: Green Material: PCB Package Contents: 1 * PCB Protection Circuit 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.