Feature: 1. 2.9 inch LCD Screen: With a 2.9 inch LCD screen, the five data (temperature, humidity, brightness, time, date) values are clearer. 2. APP Monitoring: APP whole process monitoring, built in speaker, set the upper limit, lower limit alarm, when the set upper and lower limits will be immediately alarm prompt. 3. External Probe: Support external probe (not included), accurate temperature detection, can detect ice temperature, refrigerator temperature and so on. 4. High Accuracy: More accurate measurement, built in high accuracy digital temperature and humidity sensor, even 0.1°C even small changes can be sensitive to catch. 5. Applicable Scene: Wide application range, suitable for indoor, cold storage, refrigerator and other scenes. Specification: .Item Type: WiFi Humidity Temperature Sensor Material: ABS Working Voltage: 5v Static Current: 30mA Humidity Measurement Range: 0-one hundred percentRH Temperature Measurement Range: - 19℃ to 60℃ (- 2.2℉ to 140℉) Temperature Measurement Accuracy: ± 0.3c Humidity Measurement Accuracy: ± 2% Brightness Measurement Range: 0-one hundred percent Charging Time: ≤ 2 Hours Battery Life: ≤ 4 Hours (fully Charged) Specification of Built in Battery: Lithium Battery 3.7v 500mah (shipped with Built in Battery) Wifi Standard: IEEE 802.11 b/g/n 2.4GHz (not Supporting 5G) Weight: Approx. 158g / 5.6oz Package List: 1 x WiFi Humidity Temperature Sensor1 x Usb Cable1 x User Manual 2 x Screw 2 x Expansion Rubber Plug