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. For Model: 214730-01 For Absolute ForDyson Animal ForDyson Animal Exclusive Preparation before assembly: 1. If a new core is used, please note: (1). Please use 21700 power lithium battery and small internal resistance, same model and same parameters, Do not use ordinary lithium battery for energy storage (2). please test the voltage of a single 21700 battery, and charge the single battery so that the voltage of each 21700 battery is the same . The voltage of the 18650 battery cell should be above 4.1V 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 21700 cell is the same before welding PCB. Please that the voltage of each 21700 cell is the same. The voltage of the 21700 battery cell should be above 4.1V Colour:As Shown Material:plastic Package Contents: 1set x Battery Charging Protection Circuit Board PCB 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.