Tweco 9255-1060 SMGC200 Switchable Magnetic Ground Clamp 200 Amp. It's simple to use - just turn the knob. It's easy to operate and mounts on all surfaces. Turn the knob clockwise and you instantly have a secure grip. Perfect for flat and pipe applications. Available in 200, 300, and 600 Amp sizes, these ground clamps are designed to save welders time and money. Cuts set up time. Convenient tab to easily attach ground line. Clamp can be used to ground on flat, round, and irregular surfaces. Magnetic field is simple to turn on and off, making use and clean up quick and easy. >Easy to mount: simply attach your ground line to bolt connector tab. Can withstand heat up to 176F (80C). Magnetic switch is easy to operate: a simple turn of the knob. Rated Amps: 200. Height: 2.5" (63.5mm). Width: 1.58" (40.1mm). Length: 2.19" (55.6mm). Weight: .38 Lbs.