Specification: Item type: Weather clock Material: ABS Size: Weather clock: approx. 9.7 x 15.2 x 4.5 cm / 3.8 x 6 x 1.8 inches Sensor: approx. 5 x 9.6 x 2.5 cm / 2 x 3.8 x 1 inch Weight: approx. 445 g / 15.7 ounces Use: Weather clock Battery: Weather clock and sensor require AA x 2 dry batteries (batteries not included) Indoor and outdoor humidity range: 20% to 95% RH Temperature: Measuring range of indoor temperature: -9.9C (14.2F) to 50C (122F) Measuring range of outdoor temperature: -40C (-40F) to 70C (158F) Temperature can be switched between C and F Wireless outdoor sensor: 3 channels can be connected 433.92 MHz RF transmission frequency Up to 60 meters transmission range in open area Package list: 1 x Weather clock (batteries not included), 3 x Sensors (batteries not included), 1 x User manual (language not guaranteed) Features: 3 transmitters: This weather clock supports three transmitters, capable of displaying three sets of temperature and humidity data simultaneously on one screen Optional hour system: Display can be set to 12-hour or 24-hour format; calendar function lasts until 2099 7 language options: Device supports English, German, Italian, French, Spanish, Dutch, and Danish Multifunctional: Includes two alarm settings, snooze function, low battery indicator, indoor comfort indicator, and indoor mold risk alert Battery operated: Operates on batteries only, no external power supply required, portable and convenient