Aqara Smart Lock U400 with UWB and Matter over Thread

The Aqara Smart Lock U400 is a smart deadbolt for single-cylinder doors, and it's a Thread device. It speaks Matter over Thread and Bluetooth, adds fingerprint, keypad, NFC, and a physical key, and uses Ultra-Wideband (UWB) so an iPhone or Apple Watch can unlock the door as you walk up. There's no Zigbee radio in it. This page is a researched summary of Aqara's published specs and the major reviews, not a hands-on test, and the longer U400 UWB review goes deeper on how the hands-free unlock works.

The Specs

Aqara lists the main model as DL-D06E, with variants DL-D16E, DL-D06D, DL-D16D, DL-D17D, and DL-D15D for different regions and kits. Some kits ship with an Aqara Hub M100, and the Best Buy kit is one of them. The lock replaces a single-cylinder deadbolt, comes with a strike plate, and is rekeyable.

Key hardware details from Aqara's product page start with the fingerprint sensor, which stores up to 50 prints and which Aqara quotes at 98.6 percent accuracy. The keypad has anti-peep entry for permanent, offline, and scheduled codes, and the lock also opens with an NFC card, a mechanical key, the app, voice, or an automation. It speaks Matter over Thread and Bluetooth, with UWB for approach unlock. The battery is a rechargeable Li-ion pack rated for up to six months per charge, backed by a USB-C emergency charging port. Only the outer panel carries the IP65 rating, and the operating range runs from -18C to 55C. The inner panel measures 178 x 76 x 46.9 mm and the outer panel 167 x 76 x 25.5 mm.

Aqara calls the lock BHMA certified without naming a grade. Tom's Guide cites Grade 3, but that's a single source, so confirm it with Aqara if your insurer or landlord cares.

How It Connects

Because the U400 is a Matter lock, it works with Apple Home, Google Home, Amazon Alexa, Samsung SmartThings, and Home Assistant, according to Aqara. Third-party platforms need a Thread-enabled Matter controller. UWB approach unlock adds a stricter requirement: a recent iPhone or Apple Watch plus a Thread-enabled Apple home hub such as a HomePod mini or Apple TV 4K. Aqara also describes the lock as Aliro-enabled, which is meant to extend UWB unlocking to more devices later.

Reviewers disagree on the hub question. Gizmodo says no Aqara hub is needed because the lock joins your Thread network, while ShopSavvy's summary says the bundled hub carries the firmware updates. Check which kit you're buying, since the plain lock and the hub kits are different SKUs.

Everyday Features

Aqara's page lists several daily-use touches. The lock relocks itself when the door closes, using a gyro sensor to know the door is shut. A Night Latch mode keeps the bolt thrown for the evening, and Do Not Disturb silences it when you don't want beeps. Besides Apple Home Key in Wallet, Aqara lists Samsung Wallet Digital Home Key through SmartThings, so Galaxy owners get a tap-to-unlock path as well, though it isn't the hands-free UWB one. Codes can be permanent, offline, or scheduled, which suits guests and cleaners who only need access for a window of time.

Battery and Charging

The battery is a removable rechargeable pack (Droid-Life reports 4,880 mAh), and Aqara says it lasts up to six months per charge. It warns at 20 percent, and a battery bank on the USB-C emergency port gets you in when it runs flat. WhistleOut found the charge slow, so plan to swap or top up the pack before it hits zero. That's a real change from AA-powered locks, where you just buy cells at the supermarket.

Price and Reviews

In the US, Tom's Guide lists the U400 at $269.99 and Droid-Life at $269. Tom's Guide, WhistleOut, and EFTM all call it expensive for what it does. Droid-Life says it comes in black and silver, while Tom's Guide says black only, so availability probably varies by retailer. The 9to5Mac review notes it replaces the whole deadbolt rather than fitting over your existing one, which makes installation more involved than a retrofit lever lock.

WhistleOut reported one case where the lock did not unlock on a walk-past from inside on its review unit, and ShopSavvy's roundup puts UWB reliability near 90 percent. Those are loose summaries, not lab numbers, so treat hands-free unlock as a convenience and keep a PIN or key as the dependable path.

Who It Suits

The short version of the buying case:

• Best for Apple Home households with a recent iPhone or Apple Watch
• Works with other Matter platforms, though UWB is Apple-only today
• Costs about $270 in the US
• Wants a permanent charging routine instead of AA batteries

Buy the U400 if you live in Apple Home, own a recent iPhone or Apple Watch, and want a door that unlocks as you reach it. It also suits a mixed Matter household because the lock isn't tied to one ecosystem. Skip it if you need a cheap lock, an Android-first UWB experience today, or you'd rather swap AA batteries than charge a pack. For a lever-style Thread lock at a lower price, the Aqara U300 runs on four AA batteries.

Sources

Aqara's U400 product page, Tom's Guide, Gizmodo, WhistleOut, Droid-Life, and 9to5Mac, checked on 2026-10-15.