Features: It is brand new and has premium quality It is recommend to install the product by the people who have basic electrical knowledge and hands-on ability Equipped with a 3.7-4.2V 4.5ah power lithium battery with a discharge rate of 100C and a load capacity of about 400A Comes with a charging control module, which charges the battery through the USB port, and is charged with hundreds of welding points on commonly used nickel-plated sheets within 0.1mm-0.15mm Installation Method: Weld the buzzer according to the schematic (differentiate thenegative and positive electrode) Weld the negative wire to the negative output (If you don't have a soldering iron with large power, you can increase the temperature by heating the soldering iron) Fix the battery on the back of the circuitandthe copper ears of the output wire with screws(differentiate thenegative and positive electrodeand be careful of short circuit copper foil and components of the circuit board) Fully charge after assembly (to ensure battery durability, we set a lower charging current, the chargingtimeis about 4 hours)   Specifications: Condition: New Length of welding pen: 10 cm Length of 10AWG line: 26 cm   Packing inc