Features Adjustable Uses: From 1 to 199, the mini spot welder supports 199 level adjustment to better satisfy your various needs and improve efficiency. Digital Display: Equipped with digital tube, this spot welder has clear display to show the current working status and simplify the operation. Wide in Utility: Allows for broad utilization on different batteries such as 12V 14AH-100AH battery, 18650 battery, Farad capacitance and more. Has High Safety: The whole welding process is very safe, both amateur and professional can use this welding with high safety and great ease. Simple Carrying: Designed to have a compact size and a light weight as well, the Spot welding machine is very convenient to carry to outdoor. Specification: Item Type: Spot Welder Relay Voltage and Current: 9V 500A Applicable Batteries: 1. Batteries: You can use a 12V 14AH-100AH battery. And a 14AH battery needs to be fully charged to be securely soldered). 2. Farad Capacitance: The 2.7V 3000F super Farad capacitor can be soldered by charging three super Farad capacitors in series to 8V, the maximum number of Farad capacitors in series does not exceed 4pcs. 3. Car Starting Battery: The output interface for starting the battery must be EC5, and the peak current must be below 1500A. D. Aircraft Model Battery: Please use XT60 interface, 3S-4S 3000mAh model aircraft battery, discharge rate below 60C.  Package List: 12 x Nut 8 x Screw 8 x Stud 2 x Acrylic Board 6 x Washer 2 x Insulating Sheath 1 x Tin Strip 2 x Welding Pen 1 x Motherboard 1 x Knob 1 x Relay Note: 1. Please use a battery with a continuous current of 7‑17V to ensure the power supply of the 200A‑1500A spot welding machine, otherwise it may cause damage to the motherboard.2. Do not use crocodile clips to connect the spot welding machine.3. The length of the power cord is approximately 25cms. Extending the power cord will weaken the spot welding ability and even make it impossible to carry out spot welding. Package List 12 x Nut 8 x Screw 8 x Stud 2 x Acrylic Board 6 x Washer 2 x Insulating Sheath 1 x Tin Strip 2 x Welding Pen 1 x Motherboard 1 x Knob 1 x Relay