Short answer: a floating thermometer that sends the water temperature to a display indoors, up to 500 ft away. TempPro rates it ±0.9°F between 32 and 140°F, which covers cold plunge temperatures. It comes with batteries and a tether.
Why a wireless one?
If your tub is outside, you can check the water before you walk out in a towel. The receiver also keeps the day’s high and low, so you can see how much the water warmed overnight. Why Water Temperature Tracking Matters covers what to do with those numbers.
What the listing gives
An IPX8 floating sensor with a -40 to 158°F range, a backlit receiver that also shows indoor temperature and humidity, a rope tether, and 4 AAA batteries. The two parts come pre-paired. TempPro says to line up the marks on the sensor halves when closing it, or water can get in.
How it compares
The Ice Barrel thermometer is a simple floating dial with nothing to pair or charge. Pick the TempPro if you want to read the water from inside the house.
Bottom line: worth it for an outdoor tub. Amazon sets the price.
