Nevon Express supplies wide range of high-quality digital multimeters, testing and measuring equipment which includes 0.28? 5 Wires Red Led Digital Dual DC 100V 100A Voltmeter Ammeter Without Shunt. This voltmeter ammeter has two wiring harnesses. One wiring harness is used to provide power to the meters, the two poles is with a red and black lead. It is small in size, portable and the magnitudes of voltage and current are displayed on the same screen at the same time. The three-wire harness is used for a ground that connects directly to the battery or supply ground of the load.