QuickCar's Redline Water Pressure Gauge is a 2-5/8" electric stepper motor gauge that features an adjustable warning level. The warning function changes the backlighting from white to blue and flashes as the water pressure drops below desired readings. The lightweight plastic casing is perfect for high performance uses. Gauge includes mounting hardware. 69-008 does not include sending unit (Pt.# 63-230) that is required for the gauge to function.