Magswitch 300 amp On/Off magnetic ground clamp. The Magswitch Switchable Magnetic Welding Clamp helps welders work fast with less hassle. Simple place it on a clean work surface, turn it on and start welding. No time wasted finding or making a ground point. Just incredible time savings. Featuring the patented Magswitch® technology, offers complete on/off control so metal dust just falls off - no cleaning. Strong hold (120 lbs.), works on flat and round.