2-5/8in. WATER TEMPERATURE; 120-240 ° F; LIQUID FILLED; PRO-COMPEngines 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 12' capillary tube and 1/2 NPT mounting nut are included. Incandescent Lighting Illuminates Around Perimeter Of Dial Liquid Dampening Movement Provides Smooth Pointer Movement Mechanical Instruments Provide Unmatched Accuracy No Electrical System Required For Gauge Operation Incl. 1/2 in. NPT Adapter Incl. Bulb/Socket Assembly/Red And Green Bulb Covers Incl. Mounting Hardware/Instructions