POCKET RESERVOIR POOL THERMOMETER: A pool maintenance essential. Alcohol-based thermometer with big, easy-to-read numerals DUAL DISPLAY READOUT: Dual Fahrenheit and Celsius displays. Max high temperatures: 120 F, 50 C HIGHER ACCURACY: Convenient pocket reservoir holds water for out-of-pool readings SINKING THERMOMETER: Tough plastic body sinks for better readings and stands up to daily use and abuse. More accurate than floating thermometers that will base its reading off your pool, sunlight, wind, and the air surrounding it EASY TO READY: Large, 9.5" x 1.5" profile with 2-degree increments, both Celsius and Fahrenheit