Ideal for family swimming pools, spas, pool spas, hot tubs, aquariums and fish ponds. Pool Sensor TemperatureTest Range : -40℃~+70℃ / -40℉~158℉. Host Temperature Test Range: 0℃~+50℃ / 32℉~122℉. Upgrade and optimize the waterproof sealing, to ensure that the product will not, resulting in bad product problems.