Koso Proton Water Temperature Gauge The Proton Water Temperature Gauge, crafted by Koso, is a compact and lightweight instrument crafted to deliver accurate readings of the engine's coolant temperature. Features: Provides a precise reading of engine's coolant temperature Designed to function on virtually any motorsport vehicle Operates with a Cr2032 replaceable battery Features a large LCD display for easy monitoring Comes with a removable face plate Effective temperature range: 14 140 F Adapter kit required / based on your coolant hose size