With the Sierra Black Sterling Series Water Pressure Gauge onboard, you'll be able to know if your engine's water pump is working and how well it's working.. Beneath its scratch-resistant domed glass lens the spun-aluminum dial displays the water pressure's psi rating from 0 to 40. Within the strong stainless steel bezel, the black pointer with fire-orange tip can be clearly seen in front of a white and black background. The inner perimeter of this boat gauge from Sierra is lit for nighttime viewing. Fits most stern drive and outboard applications. Size: 2". At a glance, know how well your engine's water pump is working. Scratch-resistant domed glass lens. Strong stainless steel bezel. Spun-aluminum dial displays water pressure from 0 to 40 psi. Black pointer with fire-orange tip. White and black background. Lit for nighttime viewing. Fits most stern drive and outboard applications.