Poolmaster Thermometer for Swimming Pools and Spas - Premier Collection, Analog Combo Black For measuring water temperature in pool or spa Shatter-proof body comes complete with Polyethylene cord and removable top for floating or standing options Alcohol based, easy-to-read indicator markings Temperature ranges to a maximum high of 120-degree Fahrenheit and 50-degree Celsius 8" x 1-1/4" Diameter