Sperry Instruments DSA1020TRMS True RMS Clamp Meter, Snap-Around, Digital, 10 Funct, 27 Auto-Range, 600V AC/DC, 1000A Current, Resist, Cont, Freq, Temp. Engineered to exceed the expectations of the professional electrician the DSA1020TRMS is a 10 Function/ 27 range Digital Snap-Around Clamp Meter with precise True RMS circuitry and a 1000 Amp non-contact current reading.