Euro Black 2" Digital Hourmeter Gauge Perimeter-lighted Black dial with bold White graphics, Black aluminum bezel, contoured White pointer and flat glass lens.Hourmeter operates by applying battery voltage across the gauge&';s register motor to ground. The register increments increase when the key switch in on. Route power through a normally open Oil Pressure switch to count "engine running" hours.2" - Hole size: 2.0625" (53mm)Specifications: Anti-scratch glass lens 12 VDC negative ground Can be adapted for 24 VDC systems Factory P/N MH0242*Sold as an Individual**Gauge Cover not Included This product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns. Specifications: Gauge Type: Hourmeter Voltage - Input Range (Volts): 12/24 V Gauge Size: 2" Box Set: No Series: Euro Black Box Dimensions: 4"H x 4"W x 5"L WT: 0.25 lbs UPC: 759266128354