Equipped with a 3.7-4.2V 4.5ah power lithium battery, with a discharge rate of 100C and a load capacity of about 400A.     Output through the MOS tube, and the energy will be concentrated at the end of the welding pen, and it will be heated by short circuit to fuse the nickel sheet firmly with the battery.     All this will be happened in milli seconds, simple and quickly.     It is precisely controlled by the single-chip microcomputer program without trigger the switch. Free your hands or foot pedals completely.     Self-carried with a charging control module, which charges the battery through the USB port. And it can welding hundreds of welding points on commonly used nickel-plated sheets within 0.1mm-0.15mm if fully charged.          Name: Spot Welding Tool     Battery: 3.7V, 4500mAh (included)     Item weight: 250g / 8.82ounce     colour:Green+black     Material:metal     size: 124 x 80 x 18mm / 4.72 x 3.15 x 0.71inch          Package Contents:     1 x Spot welding tool     1 x battery     1 x circuit board     2 x brazing pen     2 x screws     2 x insulated heat shrink tube     1 x USB charging cable     1 x nickel sheet          Only the above package content, other products are not included.     Note: Light shooting 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.