Hello.
Do not you have someone at home?
It is a wireless remote sencor 433 MHz.
https://www.ges.cz/en/weather-station-aok-5019-white-GES08104098.html
Just the transmitter.
https://www.aliexpress.com/item/AOK-2011-433MHz-Temperature-Humidity-Outdoor-Sensor-use-to-all-Weather-Station-RCC-RF-Thermometer-Radio/32329712106.html
It will work with this library?