Pellor Wireless Floating Pool and Spa Thermometer With Solar It is an easy way to read your water temperature from both indoors and outdoors. 433MHZ wireless receives 3 chanels water temprature. Max/min record of indoor and water temperature. Note: the batteries are not included. We don't recommend to use it in a salt water pool, it will be easy to be corrosive. Calendar from 2000 to 2099. Time alarm with snooze.