Blitz Racing Meter SD series gauges are all electronic and feature stepping motor drive for ultra accurate and smooth operation.Racing Meter SD gauges also feature Warning LED flashes if value exceeds the adjustable warning limit Peak values can be memorized and recalled Meter needle flashes if a short circuit is detected in the sensor Backlight dimmer for easier night viewing Aluminium bezel for enhanced looks No live unit required Includes Meter Holder All necessary sensors and wiring are includedRacing Meter SDVolt Gauge - 52mm