[. . . ] Remove the used battery and insert a new one CR2025 into the battery compartment. [. . . ] In normal conditions, the dual readouts should immediately appear; if however the temperature or humidity display is blank, remove the battery and re-insert it again. The acceptable level of moisture is between 40% and 60% Relative Humidity (R. Worn devices must be collected separately to optimize the recovery and recycling rates of the components therein to reduce detrimental effects on the environment and on human health. The "crossed out rubbish bin" symbol is affixed to all products as a reminder to respect the waste regulations. [. . . ] Worn devices must be collected separately to optimize the recovery and recycling rates of the components therein to reduce detrimental effects on the environment and on human health. [. . . ]