Clip-on current transformer clamp set for selective and stakeless testing that measures the ability of the earth ground system or individual electrode to dissipate energy from the site, with no disconnection from grounding system required One clamp is voltage inducing, and the second clamp is current sensing Selective testing uses one clamp and stakes to measure earth ground loop resistance values for one ground electrode; stakeless testing uses two clamps to measure ground loop resistance Both clamps have a 50.8mm/2" inside diameter