For M18 5 x 21700 Lithium Battery Case PCB for Milwaukee 18V Li-ion Battery. This can fill 5 pieces of 21700 power li-ion batteries, But this is only a shell, there is no battery inside. Please note, This battery shell is suitable for 21700 batteries, not 18650 batteries! No Original, , No Battery Cell !!!!!! This product is component without battery core. DIY (semi-manufactured goods, No battery cell!). 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. Advance notification:To use this product, you need to have some professional knowledge and experience. We do not guarantee that you can use it well. Please be kindly noted: (1). PCB color may be any color according to our stock, (2). PCB design may change with the same function and performance guaranteed. (3). The number and position of components on the PCB may change and be adjusted. Preparation before assembly: (1). If a core is used, please note: a. 21700 power lithium battery core must be selected, b. A group of 5 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. Kindly Reminder (Very Important!!! ): 1. there are no batteries in the package !!!!!! 2. If you need batteries, please don't place orders ! 3. If you don't have the knowledge of battery assembly, please don't place an order ! Color: Black Material: ABS Package Contents: 1 x Li-ion Battery Case 1 x PCB Circuit Board(R