2-5/8in. OIL TEMPERATURE; 140-280 ° F; LIQUID FILLED; PRO-COMPOne of the single most important factors in determining how your engine performs (and how long it performs between rebuilds) is proper oil temperature during operation. Knowing your exact temp allows you to make sure you've got the proper oil weight and cooling capacity. Utilizing AutoMeter's ultra precise bourdon tube meter movement, you can be assured of the most accurate possible readings of the life blood of your engine. A 6' 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