Feature: 1. Portable spot welder with quick release welding pen. Small and portable size design, easy to carry. The integrated welding pen adopts gold plated terminal, with good conductivity and low contact resistance 2. Has over current protection, low voltage protection, over voltage protection and over temperature protection. Intelligent output current. It can ensure safe use 3. Thickened pure copper strip, imported MOS tube, energy saving and longer service life. Built in high rate power battery, excellent charge and discharge performance and more stable 4. Simple operation, very good spot welding. With USB C interface, it can be fully charged in 4 hours. Built in high frequency polymer power battery, the maximum output current is up to 650A. 9 level output power is adjustable, 1st level (minimum) and 9th level (maximum) 5. With output power and remaining power indication, 1.5 second timing trigger output and automatic detection welding pen output mode. It has 4 two color indicators. When all four lights are on, it will turn off automatically after 15 minutes of use Specification: Item Type: Spot Welder Built in High Rate Battery: 5500mAh Pulse Time: 9 Levels Adjustable (Press the Button to Circle) Trigger Delay: 0.5 Seconds Applicable Charger Requirements: 5V 2.4A Independent Battery Indicator: Mode Indicator Welding Output Voltage: 4.2V (Maximum) Welding Current: 650A (Maximum) Output Voltage: 4.2V (Maximum) Output Current: 639A (Maximum) Design Current: 1200A (Maximum) Charging Port: Type C Input Parameter: 5V 1A Recommended Thickness of Nickel Strip: Approx. 0.1-0.12mm / 0.004in-0.0047in Battery Specification: Battery Type: Rechargeable Polymer Lithium Battery (Built In Battery) Model: 18650 Battery Capacity: 5500mAh. Package List: 1 x Spot Welder2 x Point Soldering Pen1 x Spot Welding Nickel Film1 x USB Cable1 x English User Manual Note: 1.Do not store in moist, seepage.Do not use in voltage and current range.2.Please allow 0 to 2 cm error due to manual measurement. Thanks for your understanding.3.Built In Battery