Boss Audio Cap20 20 Farad Power Capacitor, Black Chrome 20 Farad Digital Hybrid Capacitor with Blue Illumination 3-Digit Super bright LED voltage meter Voltage measure accurate to +/- 0.1VDC Blue illuminated window Warning tones for reverse polarity connection, over voltage (&gt;17VCD), or low battery voltage (&lt;10VDC) Working voltage: 16VDC Surge voltage: 20VDC ESR Digital Voltage Meter Black Chrome Active Light Show, 20 Farad Digital Voltage Meter Black Chrome Active Light Show, 20 Farad