Opening: a 0.38 thick blade and 0.24 thick nickel strip spot-welded together, at only half power. Introducing the AWithZ supercapacitor spot welder: main unit + accessory box (a sheet of sandpaper, a pack of nickel strip, a pair of welding pens, a power cord); refined aluminum-alloy case, model UF20B, max output current 1750A, max power 10.5kW, rated to weld 0.15 thick copper strip and 0.4 thick nickel strip; two buttons on the front, one foot-pedal port, two welding-pen ports; the welding pen has a manual switch, so you line up first and then fire, more convenient. Power on with a long press: you can set weld mode, preheat time, interval time, gear, trigger time, pulse count (screen shows 20ms, T 31°C). Plug in the pens, manual, gear 10, welding on a Li-ion cell: 0.12 and 0.24 nickel strip, bright welds with no blackening, can’t be pulled off by hand, pliers needed, both strips shred before they come off. Then a 0.38 utility-knife blade + 0.24 nickel strip, gear set to 52, judging by the sparks the power is serious, and even this thick it welds solidly, only comes off once the pliers tear it apart; a professional spot welder indeed, 99 adjustable gears cover most needs. Comments: ¥570 is too much, sticking with a relay (3); for ¥600 you can hand-build a 4-capacitor rig, though the compact looks are nice; five hundred-something; do a teardown; DIY is better; under two hundred would be fine.