new low internal resistance MOS, excellent component production, high input and output performance, automatic protection against overcharge, over discharge, and battery short circuit. Multiple protections are : overcharge protection, short circuit protection, overcurrent protection, temperature control protection, and balance protection. Offline protection: Any string of cells in the battery pack has zero voltage, and any cable is disconnected to protect the battery output. 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. Advance notification(Very Important): PCB design may change due to changes in the supply chain and processing technology. Precautions for use and assembly: 1) When welding battery leads/sampling points, be careful not to connect them incorrectly or in reverse. If a wrong connection is found, the circuit board may have been damaged and needs to be retested before it can be used again. 2) During assembly, the should not directly contact the of the battery cell to avoid damaging it. The assembly should be firm and reliable. 3) Electronic devices used for welding must be reliably grounded, and attention should be paid to electrostatic protection to prevent damage to the protective board caused by electric leakage and static electricity. 4) Be careful not to touch the components on the circuit board with lead wires, soldering iron, etc. during use, otherwise it may burn out the circuit board. 5) During use, attention should be paid to anti-static, moisture-proof, and waterproof measures. Note:due to different production batches, there are differences in printing screen printing, which does not affect the use. Colour:Green Material:FR4 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.