Time display: 12/24H optional, can display the real-time temperature of the water area where the sensor is located and the real-time indoor temperature of the host where the sensor is located on the same screen. Support recording the highest and lowest temperatures of the day. Indoor and outdoor temperature display: ℃/℉ optional. Host indoor temperature detection range: -9.9℃~+50℃ (14.2℉~122℉). Pool sensor temperature detection range: -40℃~+70℃ (-40℉~158℉). The temperature error is ±1°C and the transmission distance is 60 meters. Power supply: Indoor host: 2 x 1.5V "AAA" alkaline batteries (not included). Outdoor sensor: 2 x 1.5V "AAA" alkaline batteries (not included)