The Tempest WiFi HUB is an essential component of your Tempest Weather System. (Please note: the Tempest sensor device is sold separately.) The WiFi HUB collects data sent wirelessly from the sensor devices, performs onboard algorithmic data conditioning, and publishes the data via WiFi, UDP, and BLE. One HUB can handle 12+ sensor devices at the same location. The HUB is included with all complete weather stations. This product listing is for a WiFi HUB only (not a complete weather station) and should only be purchased if you need to replace your existing HUB.