This product is Charging Protection Circuit Board 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. Built-in IC detects cell voltage and current. and remember the number of uses! Detection and protection battery:Overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overcharge protection. All the series of for achieve low voltage shutdown. Cooperate with many power tool factories! Stable quality and anti-vibration. It is the best partner of for torque wrench and impact drill and angle grinder, etc. Color: Blue, or white, or Green, or Red, etc. any color, PCB color and version number are different according to the actual latest inventory. PCB design may change due to changes with the supply chain and processing technology. Colour: green Material: metal + plastic Package Contents: 3 set x Lithium battery charging protection circuit board assembly (not including lithium battery) 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.