Euro Black 2" Water Temperature Gauge - Metric (40Adeg to 120Adeg C)Perimeter-lighted Black dial with bold White graphics, Black aluminum bezel, contoured White pointer and flat glass lens.A temperature gauge operates by sending a low amperage current through the gauges meter to ground via a sending unit with variable resistance. The resistance of the sending units increase or decrease with the changes in pressure, temperature, etc...As the sender&';s resistance varies, the amount of current allowed to flow through it to ground changes and the meter deflects, showing the temperature.2" - Hole Size: 2.0625" (53mm)Specifications: Anti-scratch glass lens 12 VDC negative ground Perimeter-lighted Black dial Can be adapted for 24 VDC systems Factory P/N GP9124*Sold as an Individual**Gauge Cover not IncludedThis product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns. Specifications: Gauge Type: Water Temperature Gauge Size: 2" Series: Euro Black Box Set: No Voltage - Input Range (Volts): 12/24 V Box Dimensions: 4"H x 4"W x 5"L WT: 0.25 lbs UPC: 759266128149