The Orvis Encased Stream Thermometer is a tough, compact tool that helps you monitor water temperature quickly and easily while on the water. Its protective casing boosts durability, making it reliable for frequent use in rugged conditions. At just 4 1/2 inches long, it fits easily in a vest pocket or pack, and the built-in key ring allows you to clip it to a zinger or keychain so it's always within reach. Protective casing adds long-lasting durability Key ring attachment offers quick, easy access Clips to a zinger, pack, or lanyard Compact 4 1/2 in. length fits easily in gear