Poolmaster 18305 Pocket Thermometer - Basic Collection For measuring water temperature in pool or spa Large profile size with integrated pocket reservoir to capture water for out-of-pool reading Easy-to-read Farenheight / Celsius display with shatter-resistant body and alcohol-based indicator Reads maximum high temperature of 120 degrees F, and 50 degrees C 9-5/8" long and comes complete with Polyethylene cord