GEREE Blue Digital Ammeter LED Display 0.56" Digital DC 0-100A Ammeter Amp Ampere Meter Connect with 100A/75mV Ammeter Shunt DC 0-100A measuring range; DC4.5-28V power source. 48x29x21mm dimensions, 45.5x 26.5 Cutting size, easy to mount. 0.56" Digital Tube with clarity and brightness LED display. With 100A / 75mV shunt, easy to connect. Ground wire of testing end and power supply temninal is the same wire; quick refresh of about 500 ms.