This is a handy 150 mm (6 inch) capacity malleable cast sliding arm clamp, with an 10.5 mm (0.413 inch) diameter hole for connecting a welding ground wire. This ground clamp is rated for 400 Amps. Easy to use sliding T-bar handle on clamping spindle. Sliding arm clamps are quick to adjust & affix to your work pieces. BESSEY. Simply better.