Features: 30 Power Gear Modes: the output power gear is adjustable, 1-30 gears cycle, up and down touch buttons control. Intuitive Display: with a 0.91-inch OLED screen for clearly display the voltage, current, power, battery level, and other values at different menu interface. Built-in Rechargeable Battery: inbuilt 5500mAh high rate rechargeable polymer lithium battery as the energy supply for the spot welding machine that can support long time use to ensure the welding job done. Stable and Reliable: mini portable soldering pen kit is easy to use, perfect for you to construct your own battery packs and other DIY projects. Automatic Power-off: it will automatically power off if it is not used for 10 minutes to save battery power. Accessories: equipped with a pair of 14.5-inch(370mm) split-type welding pen that designed with the detachable 2mm gold-plated copper soldering needle, a roll of 2 meters long nickel sheet(0.12*8mm), and a charging cable. Specifications: Material: Aluminum Input Voltage: 100-240V, 50/60Hz, 0.35A Output Voltage: 4.2V(MAX) Output Current: 650A(MAX) Design Current: 1200A(MAX) Charging Port: Type-C, 5V@3A Recommended Nickel Strip Thickness: 0.1~0.15mm Lithium Battery: 23Wh Battery Capacity: 5500mAh