2PCS: 

https://www.banggood.com/2Pcs-SONOFF-SNZB-02D-LCD-Smart-Temperature-Humidity-Sensor-APP-Real-time-Monitoring-Work-with-ZB-Bridge-P-or-ZB-Dongle-or-NS-Panel-p-2003317.html

Description:

【Remote Real-time monitoring】

SNZB-02D sensor will monitor the temperature and humidity in real time on the APP remotely or display screen, with up to 120m/400ft coverate.

【High Accuracy & 5s Fast Refresh】

Built-in Swiss-made smart hygrometer sensor that gives you more accurate readings maintaining ±0.2°C/±0.4°F accuracy in temperature and ±2%RH accuracy in humidity, refreshes readings every 5 seconds.

【Large LCD screen display】

Use large LCD display to view the real-time values of temperature humidity clearly and dynamically, the intuitive display icons let you check the room conditions and battery status even easier than ever.

【App notifications】

You’ll receive instant alerts from your phone when the temperature or humidity exceeds your set comfort level.

【Data Storage & Export】

Up to half-year free cloud storage, and most accurate enough to view hourly data, you can also check the highest and lowest values at any hour or day and data can be exported as files.