The protection board is for 5 series Li-ion batteries, mainly used for electric power tools. It uses special IC for 5S lithium batteries as processor to detect real-time voltage, charge and discharge current and ambient temperature of each battery. Stable various protective functions for charging and discharging, such as overcharge protection, over-discharge protection and short circuit protection. Note: Due to different production batches, there are differences in product appearance, but it does not affect usage. Colour:Blue Material:PCB Package Contents: 1 * Battery Protection 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.