4Pcs BL1830 Li-Ion Battery BMS PCB Charging Protection Board 1. The integrated dual IC detects the voltage of each cell. And remember the number of uses! 2 Each battery can be detected and protected. Overheat protection, overvoltage protection, overvoltage protection, overload protection. 3. The entire new for Makita series achieves low voltage shutdown. Cooperate with many power tool factories! 4. Stable quality and anti-vibration. It is the best partner of for Makita torque wrench and impact drill and angle grinder. Colour:blue Material:PC+Metal Package Contents: 4 * Battery Protection Board Only the above package content, other products are not included. Note: Light shooting 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.