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Small white rectangular sensor with a matching magnet, smooth matte finish

Shelly

Shelly Blu Door/Window Sensor White

SKU CH-NJZB-3VHXJ

A Bluetooth door and window sensor that sends instant open alerts to your phone and triggers automated scenes for security or energy saving

  • Connection protocolBluetooth
  • Product typeDoor / Window Sensor

Color White

  • Instant alerts when doors or windows open unexpectedly
  • Automated heating shut-off when windows are opened saves energy
  • Works with Google Home and Alexa for voice control
  • Measures ambient light and tilt angle for extra data
  • Create custom scenes triggered by sensor state changes

Door & Window Monitoring

The Shelly Blu Door/Window Sensor is a Bluetooth-operated device that detects when an entry point is opened or closed. It sends real-time alerts to the Shelly Smart Control app on iOS or Android so you can monitor activity remotely. The sensor integrates with Google Home and Alexa for voice control and routine triggers. It suits homeowners wanting a simple way to secure doors, windows, balconies or garage entrances.

Compact Build & Mounting

The sensor features a minimalist white finish and a discreet form factor designed to fit unobtrusively on frames and sashes. Installation is quick and does not require wiring, allowing flexible placement on a wide range of surfaces. Its wireless Bluetooth connectivity means there are no cables to route, keeping entryways tidy while maintaining a reliable link to the home automation hub.

Bluetooth Range & Ecosystem Limits

Operation depends on a stable Bluetooth connection between the sensor and a compatible gateway or smartphone acting as a bridge. Thick walls, metal frames or long distances can weaken the signal and delay notifications. Advanced automation scenes require the sensor to remain paired within the Shelly ecosystem or a supported third-party platform. Users needing wired reliability or integration outside these environments should consider alternative technologies.

How it compares

Measured against everything we stock in Alarm Kits & Motion Sensors, at today’s prices. Recalculated every night.

Price $14.99
Cheaper than about 88% of the 180 comparable items (median $30.99).

Specifications

Product
Product typeDoor / Window Sensor
Connectivity
Connection protocolBluetooth

Questions about this item

What Bluetooth protocol does the Shelly Blu Door/Window Sensor use?

It communicates over Bluetooth to send open/close events and sensor readings to the Shelly Smart Control app on iOS or Android.

How much clearance is needed to mount the sensor and its magnet?

The sensor body and the separate magnet piece are small enough to fit on standard door or window frames; both include adhesive backing for tool-free placement.

How do I pair the sensor in the app, and what step is often missed?

Open the Shelly Smart Control app, add a new Bluetooth device, then pull the battery tab on the sensor to power it up — skipping the tab removal is the common reason pairing fails.

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