The Wattmeter / Varmeter module is fitted with one wattmeter and one varmeter and is designed to indicate direct measurement of active and reactive power in balanced three-phase circuits. Each meter has a zero-center cable scale to show the direction of power flow. Its electronic design uses voltage and current sensors to sample line voltage and current. Voltage and current circuits are internally connected so that students only have to connect the "line" and "load" terminals of the module.