Adopt thick copper bar, help enhance the working efficiency, and suitable for long service time. Integrated , beautiful and , 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 , can support long time use, stable and , wear resistant and effort saving. Suitable for spot welding machine. Specifications: Name: Spot Welding Pen Welding-needle size: 50 x 3 x 3mm / 1.97 x 0.12 x 0.12in Item size: 155 x 45 x 25mm / 6.10 x 1.77 x 0.98in Item weight: 250g / 8.82ounce Colour: Yellow Material: copper Package Contents: 1 x Spot Welding Pen Note: connect to 12 V external power source. Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.