About this item 1. The use of a double waterproof ring for good waterproof performance; 2. We have had this thermometer for a longer time than other foreign models, and it measures the water temperature more accurately. In summer, the surface water temperature is high, other similar products are too short, the water temperature will be much higher! The leakage rate of other models is too high! The key is the waterproof performance! 4. We are the best waterproof product in this category! Note: The power-up sequence must be performed in the order shown in this section (insert the batteries into the remote control transmitter first, then into the display console).