Model 1(5 gears)  Features: 1. Lithium battery protection. 3. Low power consumption function: long press to turn on/off, short press to cycle through 5 gears, all operations can be performed quickly and concisely.  4. Thermal optimization: This product uses 2 ultra-high rate model airplane lithium batteries, and the safe discharge peak value can reach 630A+. All high-current wiring is optimized by infrared thermal imaging to better share the discharge current. 5. Portable spot welding machine, with quick release welding pen. 6. The integrated solder pen uses gold Plate terminal, with fine conductivity and low contact resistance. 7. Adopts a micro USB charging interface for easy charging. 8. Fine workmanship and good performance. 9. Easy to use. Instructions: 1. Press and hold the spot welder for 3 seconds, the buzzer will sound once, then it can be turned on/off. Low power consumption hardware and software design. The measured current is a few μA after shutting down, so there is no need to worry that the spot welder will be used up after a long time, which will affect the life of the power supply. 2. Short press the button to increase the gear by one. The gear level can be memorized when it turns on again. Total six gears cycle. 3. The spot welding machine can automatically detect welding pens. Trigger after touching nickel plate for 0.8s, no manual / foot trigger or interval trigger at all. First-class operation experience. 4. The special power management and software design of the welding machine, the welding process is not reset, and the gear is not returned to zero. When the power changes, the solder joint may become weak, and the user can increase the gear at this time. It is recommended to charge as soon as possible. 5. When charging, the power light reminds in the form of breathing light, and the light is always on when it is full. To prevent accidents during charging, the welding function is not available during charging. 6. Comes with charging management control module. It can be charged through the mobile phone charging head (5V, output current is at least 1A), equipped with a USB charging cable. 7. Comes with 50C discharge high rate power supply. After fully charged, the machine can weld hundreds of solder joints for common  nickel-plated sheets within 0.1mm-0.15mm.          Product List: 1 x Host 2 x Soldering Pen 1 x Type-c Charging Cable 1 x 2m 0.1mm*8 Nickel Sheet 1 x Instruction Manual  Model 2(9gears)  Features: 1. 9 levels of power adjustable 2. 2A high current charging, fast charging speed. 3. Power bank USB output function (5V MAX2.4A)/, 4. The soldering pin can be replaced, and the soldering pen is integrated and the soldering will not be hot 5. Program update, more user-friendly operation 6. Free 2m nickel sheet Specification： Charging voltage: 5V Charging current: 2A USB output voltage: 5V. USB output current: MAX 2.4A Welding voltage: 4.2V Welding current: MAX 650A Charging port: Type-c Product size: 103* 83*29mm Instructions For Use: 1. First charge the product, save it at low voltage by default, and fully charge it for welding test.