# arre Contact Sensor

arre Contact Sensor is a low-cost direct-Matter trigger for a door, window, cabinet, or drawer when Thread already reaches the frame. Buy it for basic open and closed state, but treat arre's battery estimate conservatively and verify the exact alert behavior in your platform before scaling out.

Canonical page: https://matterhome.io/devices/arre-contact-sensor
Markdown page: https://matterhome.io/devices/arre-contact-sensor.md
Author: Matterhome Editorial Team
Author profile: https://matterhome.io/authors/matterhome-editorial-team
Editorial lead: JC Martinez
Editor profile: https://matterhome.io/authors/jc-martinez

## Device Facts

- Brand: arre
- Model: Contact Sensor
- Product type: Matter-over-Thread contact sensor
- Category: Sensors
- Connection: Matter over Thread
- Matter status: arre sells the white Contact Sensor SKU Z0-SA5V-45GT as a direct Matter-over-Thread sensor; its current product page requires a compatible Thread border router but no separate arre hub.
- Launch date: 2025-01-29
- Thread border router required: Yes
- Brand hub required: No
- Typical price range: $23.99 sale / $29.99 list price
- Markets: North America
- Review status: Compatibility guide
- Product image: https://assets.matterhome.io/content/devices/arre-contact-sensor/product.11ff219f3d248a983fce/source.webp
- Product image alt text: White arre Contact Sensor and magnet shown side by side
- Product image source: https://arrehome.com/cdn/shop/t/10/assets/rd-contact-hero.png?v=32524369084903686071785432450

## Ecosystem Support

- Apple Home: Supported
- Google Home: Supported
- Alexa: Supported
- SmartThings: Supported
- Home Assistant: Not listed

## Best For

- North American buyers adding one inexpensive contact sensor to an existing Thread home
- Doors, windows, cabinets, and drawers that need a simple open-close automation
- Buyers who prefer a common CR2032 battery over a less familiar cell

## Skip If

- No compatible Thread border router serves the final mounting position
- Home Assistant support or identical notification behavior must be documented before purchase
- A local siren, tamper alarm, or detailed event history is required
- The purchase depends on the black finish that is not currently selectable

## Setup Notes

- Press the front button to activate pairing; five LED blinks indicate pairing mode, while two blinks indicate that the sensor is already commissioned.
- Scan or enter the Matter code printed on the side of the sensor in a controller app that can reach a Thread border router.
- Test open and closed state plus the intended notification or automation from the final mounting position before attaching the sensor.
- Store the Matter setup code safely, and hold the front button for five seconds when a complete reset and re-pair are required.

## Known Limitations

- The current product page estimates roughly two years from one CR2032, while arre's linked support page says it advertises up to one year depending on use.
- arre lists four ecosystems but does not document identical notification, history, battery-status, or automation behavior across them.
- The current store exposes only the white variant even though some product copy still mentions a black finish.
- Matterhome has not tested commissioning, Thread range, state latency, battery life, notifications, multi-admin behavior, or long-term adhesive mounting.

## Pros

- Direct Matter-over-Thread contact state without a separate arre hub
- Current $23.99 price undercuts many established Thread contact sensors
- Uses a replaceable CR2032 battery
- Current product page lists Apple Home, Google Home, Alexa, and SmartThings

## Cons

- Requires a compatible Matter controller and Thread border router
- Battery-powered sensor does not extend the Thread mesh
- Official arre pages give conflicting one-year and two-year battery guidance
- Home Assistant is not listed for this exact retail product

## Sources

- https://arrehome.com/products/arre-contact-sensor-with-matter-support
- https://arrehome.com/products/arre-contact-sensor-with-matter-support.js
- https://arrehome.com/pages/contact-sensor
- https://cdn.shopify.com/s/files/1/0565/5920/6582/files/Contact_Sensor_-_Instruction_Manual.pdf?v=1738191173
- https://arrehome.com/pages/arre
- https://arrehome.com/cdn/shop/t/10/assets/rd-contact-hero.png?v=32524369084903686071785432450

At $23.99, the arre Contact Sensor is easy to understand: it is a relatively inexpensive way to make a door, window, cabinet, or drawer report whether it is open or closed. It pairs directly through Matter over Thread, so there is no arre hub to buy. That price is useful only when a compatible Matter controller and Thread border router already serve the mounting point.

Matterhome has not tested the sensor. This guide covers the currently available white variant, Shopify SKU `Z0-SA5V-45GT`. arre's linked manual identifies the underlying model as `TCS-07505`, a designation carried over from the company's earlier TUO branding.

## Price is the reason to start here

arre lists Apple Home, Google Home, Alexa, and SmartThings for the sensor. Its core job is appropriately narrow: separate the magnet from the main unit and the platform receives an open state; bring them together and it receives a closed state. That can turn on a closet light, warn that a side door opened, or pause heating while a window is open.

The current $23.99 sale price is below the typical price of Aqara Door and Window Sensor P2 or Eve Door & Window. The arre sensor also uses a common replaceable CR2032 battery. It does not add a local siren, strengthen the Thread mesh, or guarantee useful history in every app. Buy it because contact state solves a named routine, not because another sensor tile looks reassuring on a dashboard.

The battery claim deserves conservative planning. arre's current product page says the included CR2032 lasts about two years under normal use. The linked technical page says the battery should exceed two years but also says arre advertises up to one year depending on use. Those statements do not agree. Budget for annual replacement and treat anything longer as upside until real use proves otherwise.

## Prove the complete alert

A contact tile appearing in an app is only the first test. The routine also needs the correct device name, prompt state changes, the intended notification or action, and access for every household member who depends on it. arre does not document whether notification controls, history, or battery status behave the same way in each listed ecosystem.

Home Assistant is not listed for this exact product. General Matter support makes commissioning plausible, but it is not product-specific evidence that the desired contact and battery entities will appear in the current Matter server. Verify that path before buying specifically for Home Assistant.

## Pair it before mounting

The official manual says to press the front button to activate the sensor. Five LED blinks indicate pairing mode; two indicate that it is already commissioned. Scan the Matter code printed on the side in the chosen controller app, then keep that code somewhere safe for a later reset or move to another fabric.

Dry-fit both pieces and test from the final frame before using adhesive or screws. A desk test beside the border router says little about a metal exterior door, a recessed window, or a detached garage at the edge of the Thread network. The sensor runs on a battery and does not route traffic for nearby Thread devices, so another powered Thread accessory may be needed to improve coverage.

If the sensor must move to a different Matter setup, holding the front button for five seconds performs the complete reset described in the manual. Repeat commissioning and test the full routine again before remounting.

## Which contact sensor should you buy?

[Aqara Door and Window Sensor P2](/devices/aqara-door-window-sensor-p2) costs more but has broader product-specific ecosystem documentation and includes a thin magnet plate for difficult frames. [Eve Door & Window](/devices/eve-door-window) has a more established Thread product history and richer Eve app history for supported setups, but it uses a less familiar half-AA battery and usually costs more.

Choose arre when the lower price and CR2032 battery matter, Thread already reaches the exact frame, and basic contact state is enough. Buy one first. If the final placement, alerts, and battery reporting all behave correctly in the household's main platform, the sale price can make additional doors and windows a sensible second purchase.