ABS Jio-Temperature-Humidity-Smart-Home-Safety-Sensor-Device-Automation

This sensors reports various air quality metrics such as temperature, humidity and pressure. I have a ton of those placed in various spots around my apartment. Notable locations are inside the air ventilation system, fridge, bedroom and outside the window. They're so small that they can fit anywhere. I use these for air quality monitoring as well as to provide information to Google Home so I can ask it 

These sensors communicate over the Zigbee protocol. Zigbee uses a 2.4GHz band that's similar to Wifi. It's main advantage is however that it forms a mesh network. So a tiny sensor running on a button cell doesn't have to connect at a central hub but rather uses the nearest mains powered device to repeat its signal. Since most of the devices are also controlled over Zigbee I in any project have a fairly extensive Zigbee mesh and these sensors never need to broadcast very far. In general the button cell of most of the sensors seems to last between 1-2years before needing to be replaced.