RHT-Air+ Wireless Temperature and Relative Humidity Transmitter. Temperature Range -10 to +70°C (Accuracy ±0.2°C), Relative Humidity Range 0 to 100%RH, (Accuracy ±1.5%RH). Display: 2 Line, 4 Digit LED, showing both temp & %RH. Power Supply: Internal battery or 5V USB C. Radio Transmission via 858MHz, max 3Km line of sight. Internal Memory for up to 15,000 values (Temp & %RH). Micro USB port for configuration, download and diagnostics via NXPerience software. Operating Range, -10 to ...