Please read this before you buy 1. This sensor must match the for xiaomi multifunctional gateway or Aqara gateway hub ( need to be purchased separately ) to use.2. Aqara gateway hub is required to make this sensor to work with HomeKit. Specifications Model: WSDCGQ11LM Battery: CR2032 (included) Wireless Protocol: Zigbee Dimensions: 36 36 9 mm (1.42 1.42 0.35 in.) Temperature Range and Precision: -20~+50C, 0.3 (-4~+122, 0.5F) Humidity Range and Precision: 0 100% RH (non-condensing), 3% Atmospheric Pressure Range and Precision: 30 kPa 110 kPa, 0.12 kPa App: Apple Home app (iOS 10.3 or later), Aqara Home app (Android 5.0 or later, iOS 10.3 or later), Mi Home app Highlights ZigBee wireless connection, no wiring required Monitors temperature, humidity, and atmospheric pressure in real time. REMOTE MONITORING: When the room temperature reaches above or below a certain threshold, the Aqara Temperature and Humidity Sensor can send a push alert to your phone or trigger other devices. HOME AUTOMATION: The Aqara Temperature and Humidity Sensor can control other connected devices such as Aqara Smart Plug to ensure that your fan or humidifier maintains a constant level of comfort for you and your family.ACCURATE MEASUREMENT: Utilizes high-quality sensor from the industry-leading manufacturer, Sensirion. BUILT-IN AIR PRESSURE SENSOR: Monitors the ambient air pressure in the room. Can work with Homekit, Mi Home Packing List Temperature and Humidity Sensor x 1Sticker x 1Quick Start Guide x 1 Aqara Temperature and Humidity Sensor Monitors temperature, humidity, and atmospheric pressure in real time.No Wiring Required | Temperature and Humidity Reminder | 2 Years Battery Life* An Aqara hub is required. Data review The current data is displayed in the app. An alert notification will be sent to your phone when abnormal environment is detected.