Hour meter, DC voltages from 12 volt thru 36 volt nominal. Heavy duty glass-reinforced polyester body. Internal shock shields & grommets protect movement from shock & vibration damage. Fits 2-1/4 inch opening, three(3) mounting screws with nuts and two(2) blade terminals included. Net Weight (lbs) 0.19 Brand TISCO 2 Inch Round 3 screw mount hour meter Solid State Electronic Drive Circuit Quartz Crystal for Accurate Timing 10-80 VDC, Polarity Insensitive Time Scale: 6-difits; Automatic Recycle to Zero Non-reset Power Consumption: Less than .03 Watts at 12 VDC; .7 Watts at 48 VDC Temperature: -40°F to +185°F (-40°C to +85°C) Vibration Resistance: Withstands 10-80 Hz at 20g;s Max. (SAE J1378) Shock: 55g at 9-13 ms (SAE J1378) Humidity: 95% (SAE J1378) Protected from Alternator Load Dump Inductive Switching High Impact, Tamperproof Plastic Case No Battery Back-Up Required UL/cUL Recognized, CE & RoHS Compliant IP67 Made in the USA