Klein Tools CL220 Clamp Meter is an automatically ranging true root mean square (TRMS) digital clamp meter that measures AC current and NCVT via the clamp, AC/DC voltage, resistance and continuity via test-leads, and temperature via a thermocouple probe. Exclusively designed from the ground up by electricians for electricians. Years of field research, combined with extensive input from electricians across America, inspired the development of meters loaded with innovative, time-saving features.