This portable spot welder machine is a game-changer for DIY enthusiasts and alike. With its compact design and built-in power supply, you can now easily weld- nickel sheets. DIY spot welding, which combines the built-in power supply and the welding pen into one, without the need for an external welding pen to easily weld-, make your spot welding project easier and . The integrated soldering pen uses gold-plated terminals, with good conductivity and low contact resistance. Miniature USB charging interface is adopted for easy charging. Fine workmanship and good-performance.Easy to use&Long service life. Operation : 1. Shot press the key to turn in the machine,long press the key for 3 seconds to turn the machine; 2. After startup,the module is in automatic welding mode,welding once in 2 seconds; 3. After starting, you can change the output power of the spot welding machine by pressing the key,and the blue light indicates the gear; 4. that the battery welding surface in free of rust,clean and smooth; 5. that the nickel sheet is clean and smooth; 6. Welding head detection contact metal,can be output once,after lifting can be welded next time; 7. Set up the spot welding machine,appropriate pressure to make the welding needle and nickel,nickel and battery contact is good,no hanging on bad contact,can be welded.Different nickel thickness,using different gear,not the greater the power effect is batter,you can try which gear is more suitable. Model:-401 Charging:Micro-USB 5V Battery:18650/21700 Lithium-Battery Note:Do not for touch-any metal parts of the fuselage-with a welding pen. Colour:Black Material:aluminum alloy Size:about 249.7x57.83x24.45mm/9.84x2.27x0.96in Package Contents: 1 * Spot Welder Machine 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.