Review on Portable DIY Mini Spot Welder - 4 Output Power, Household Nickel Belt Spot Welder with Aluminum Alloy Shell and 2Pcs Welding Pen - Ideal for 18650 Battery DIY Projects by Justin Cage

I don't remember the exact numbers but I believe it was only designed for spot welding 0.15mm nickel strips and I bought 0.2 -mm nickel strips. As long as I kept it at the highest level it worked great and I didn't have to buy a thinner nickel and then wait for it to arrive. Good product. Sturdy (I've dropped it a couple of times) and for the size and money, I highly recommend it.