Thumb Score: +18
Use AA batteries and it will work during power outage. The system transmits on 433.92mhz, my home assistant is able to read both sensors via a SDR receiver.
https://www.amazon.com/dp/B07XD68GX6[list][*]Digital Thermometers: Includes one refrigerator thermometer and one freezer thermometer that transmit readings to the digital display[*]Easy-to-Read LCD Display: Comes with magnetic backing for fridge mounting, a keyhole for mounting on a wall, and a foldout stand for countertop placement