This is a kind of fine quality spot welding pen, adopt thick copper bar, help enhance the working efficiency, and suitable for long service time. Integrated design, beautiful and neat, with fine heat radiation effect. There are dual springs on the handle, each welding pen can expand and contract independently. Built-in limit switch, one hand operation, do not need foot pedal. You can have a try. Features: Adopt thick copper bar, help enhance the working efficiency, and suitable for long service time. Integrated design, beautiful and neat, with fine heat radiation effect. There are dual springs on the handle, each welding pen can expand and contract independently. Built-in limit switch, one hand operation, do not need foot pedal. With comfortable hand feelings, can support long time use, stable and reliable, wear resistant and effort saving. Suitable for 18650 battery spot welding machine. Note: please connect to 12 V external power source. Specifications: Name: Spot Welding Pen Color: white, blue, green, black (optional) Welding needle size: 50 * 3 * 3mm / 1.97 * 0.12* 0.12in Item size: 155 * 45 * 25mm / 6.10 * 1.77 * 0.98in Item weight: 250g / 8.82ounce Package size: 200 * 100 * 50mm / 7.87 * 3.94 * 1.97in Package weight: 234g Packing List: 1 * Spot Welding Pen