It can fill 10 pieces of 21700 power Li-ion batteries. But this is plastic shell, there is no battery inside. No Original, New, No Battery Cell !!!!!! This product is component without battery 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. Functional characteristics: (1) High temperature protection for charging and discharging, low temperature charging protection. (2) Temperature control parameters are externally adjustable. (3) Overcharge detection protection. (4) Overdischarge detection protection. (5) Three stage overcurrent protection. (6) Externally adjustable during the first and second of overcurrent delay. (7) Battery disconnection protection function. (8) resistor disconnection protection function. (9) Short circuit protection function. (10) Suitable for original (for ) chargers. Notes: After combining the battery pack and this protective board, if there is no voltage output during the initial power on, please activate it with a dedicated charger. Preparation before assembly: (1). If a new core is used, please note: a. 21700 power lithium battery core must be , b. A group of 5/10 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: that the voltage of each cell is the same before welding PCB. Note: 1. PCB color may be any color according to our stock, 2. PCB design may change with the same function and performance guaranteed. Color: Red & Black Material: plastic Package Contents: 1 * Battery Plastic Case 1 * Protection Circuit Board (random colors, don't accept the specified color) 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.