Rockville RXC2D 2 Farad Stiffening Power Capacitor with LED Digital Volt Meter Rockville RXC2D 2 Farad Stiffening Power Capacitor 2 Farad/12 Volt Stiffening Capacitor with 24 Volt Surge Capacity Lucite Encapsulated Display and Logic Circuitry. Red LED Digital Voltage Display. Blue Led Flashing Charge and Discharge Metering.