Extech MA140 Handheld True RMS 300A Mini Clamp Meter + NCV is designed to take accurate AC current measurements with True RMS technology even for noisy, distorted, or non-sinusoidal waveforms. The Extech MA140 features a 0.8” (22mm) jaw opening for conductors up to 300MCM, innovative smart auto sense feature, integrated non-contact voltage (NCV) detector, inrush current measurements, and more.