Features: brand new and high quality The spot welder pen comes standard with a pair of Japanese concentric ball‑point needles, which is effective. This 18650 battery spot welding pen, suitable for long‑term work, improve work efficiency, made of thick brass bar. The appearance is clean, and the heat dissipation is fast. It is suitable for assembling battery packs. Brass bars are cleaned and protected by strong acid to ensure the brightness of the brass bars. The handle has double springs to expand and contract, and each soldering pen is independently expandable, with moderate force control. Not happen that the common one‑piece spot welding pen cannot attain the pressure balance of the two welding needles, resulting in weak welding, large sparks and low work efficiency. Specifications: Material: Copper Size:15.5x4.5/6.10x1.77inches Package Includes: 1 x Spot Welding Machine note: There may be an error of 0-1 for cm when measuring the product.