Ubiquiti USL-Environmental SuperLink Environmental Sensor

The Ubiquiti USL-Environmental is a battery-powered wireless sensor that monitors temperature, humidity, ambient light, and water leaks over long range via Ubiquiti's proprietary SuperLink protocol. It is designed to extend environmental monitoring to locations where running cables or relying on WiFi or Bluetooth is impractical, including basements, plant rooms, roof voids, equipment closets, and outbuildings.

Water detection is handled through multiple on-device contact points: two sets on the base detect standing water or flooding, while a dedicated set on the top detects drips from above such as condensation or leaking pipes. A 3.5mm AUX jack on the device also accepts a compatible external probe for expanded coverage in areas the sensor cannot directly reach.

The sensor communicates exclusively through a USL-Gateway (sold separately), which relays events to UniFi Protect over the network. Alerts for out-of-range temperature, humidity, or water detection are delivered as push notifications or webhooks via UniFi Protect's Alarm Manager.

Running on a single CR123A lithium battery with up to 6 years of battery life, the USL-Environmental spends most of its time in low-power sleep mode, waking only to report sensor events or on a configured interval. The function button forces an immediate sync with the gateway and highlights the device in the UniFi Protect device list to simplify identification during installation.

The polycarbonate enclosure is IPX5 rated and mounts via adhesive, magnet, or screw fixing to suit most surfaces, with the galvanised steel mount plate included.

Note: A USL-Gateway is required for this sensor to function.