This is the Plastic Case, it can fill 10 pieces of 18650 li-ion power batteries, But no battery cell in it!!!!!! No Original, ,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. Please be kindly noted: PCB Protection Circuit Board design may change due to changes with the supply chain and processing technology. If you have any objection to the following two items,please do not order! 1.PCBA color may be any color according to our stock, 2.PCBA design may change with the same function and performance guaranteed . Once you place an order,you agree to the above two terms by default,and you are not allowed to submit disputes for the reasons of "different colors,design changes,wrong version of goods"and so on. Preparation before assembly: (1)If a new core is used,please note: a.18650 power lithium battery core must be (discharge current 10C), 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. Colour:Black Material:plastic note:The color of the protection board is random,no specified color is accepted Due to different batches, there may be differences in product appearance and printed text, which not affect use Package Contents: 1 x lithium battery case with 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.