2-5/8in. WATER TEMPERATURE; 140-280 ° F; ULTRA-NITEEngines don't like high water temperatures, Heat is the enemy of performance and reliability. Keep tabs on your temps with the most accurate, quickest responding water temperature gauge on the market. AutoMeter's advanced bourdon tube meter movement provides unparalleled performance in the most demanding applications. A 6' capillary tube and 1/2 NPT mounting nut are included. Luminescent Dial Glows Green At Night For Dimly Lit Tracks For Racing Use Only Not Intended For Street Applications No Electrical System Required For Gauge Operation Mechanical Instruments Provide Trusted Accuracy And Durability Incl. 1/2 in. NPT Adapter Incl. Bulb/Socket Assembly/Red And Green Bulb Covers Incl. Mounting Hardware/Instructions