For those who own multiple instruments!! Great value set sale!! -------------------- A reliable item for managing your musical instruments! A high-performance thermometer/hygrometer with Bluetooth and app connectivity! You can manage the temperature and humidity of not only acoustic guitars, but also ukuleles and other classical instruments with a smartphone app! ★Check the temperature and humidity using the smartphone app without opening the case! ★If the set temperature and humidity levels are exceeded, an alert will automatically be sent to your smartphone! ★Graph changes and trends in temperature and humidity. Check the values on a daily or monthly basis!! ★With Gateway (sold separately), you can check the temperature and humidity from your smartphone via the Internet even when you're out and about! *Up to 10 devices can be paired with one Gateway. *The dedicated app (free) is compatible with both iOS and Android. Powered by a CR2032 button battery, it has a lightweight and compact design weighing just 33g (including battery weight). A 26mm diameter E Ink high-resolution display with a wide viewing angle and excellent visibility. The sensor uses a globally standard temperature and humidity sensor manufactured by the Swiss company SENSIRION. Magnets are also installed on the back of the display and sensor units. The sensor part is inserted inside the instrument and sandwiched between the wood panel. It can be fixed and attached by automatic magnet suction. Therefore, the only way to measure the temperature and humidity inside an instrument is to This is one of the major features of this Lee Guitars thermometer/hygrometer. It also has Bluetooth 5.0 functionality, and by pairing it with a free dedicated smartphone app, Even if your instrument is stored in a case, you can still use it with your smartphone within Bluetooth range. You can check the temperature and humidity using the smartphone app without opening the case. Furthermore, this data is automatically recorded and can be managed within the app. -Product Information- E-ink high-resolution display (26mm diameter) World-standard temperature and humidity sensor from Swiss company SENSIRION Equipped with Bluetooth 5.0 Powered by CR2032 button battery Weight: 30g Temperature measurement range: 0℃ to 50℃ Humidity measurement range: 0 to 99% RH (no condensation)