Built-in dual IC detects cell voltage. And remember the number of uses Detection and protection battery:Overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overcharge protection. Stable quality and anti-vibration. It is the best partner of torque wrench and impact drill and angle grinder. PCB design may change due to changes in the supply chain and processing technology. The white characters on the product are random, don't accept the specified color. Colour: blue Material: PCB Package Contents: 3 * Circuit Board Only the above package content, other products are not included. Note: Light 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.