TFA MusiControl Thermo-Hygrometer, fully digital, for the control of temperature (-10°C to +60°C) (precision ± 1 °C) and humidity (1% to 99%) (precision ±4% from 35...75%, otherwise ±5%), for the best storage of musical instruments, max.-min.-function, clef as indicator for ideal storage conditions, alarm function, detailed instructions included, comes with 2x 1,5V AA batteries.