Aqara has introduced a new product called the Smart Lock U400, which is now available. This lock uses ultra-wideband, or UWB, technology for a hands-free unlocking experience. When an authorized user with an iPhone or Apple Watch approaches the door, the U400 recognizes them and unlocks the door automatically. This is different from other smart locks that often require tapping, entering a code, or using Bluetooth. The U400 uses precise tracking based on Time of Flight and Angle of Arrival to make sure the door only unlocks if the user is coming from the outside. This helps prevent the lock from opening when someone is just walking by or is inside the house.
The Smart Lock U400 is designed to work closely with Apple devices. Users can add a digital home key to Apple Wallet on their iPhone or Apple Watch. This means that anyone in the house who is set up in the Apple Home app can use their device to unlock the door just by walking up to it. The lock also allows for managing guest access through the app, making it easy to let others in as needed. For people who do not use Apple devices, the lock also supports NFC cards from Aqara, fingerprint recognition, one-time and recurring codes, remote unlocking through mobile apps, and even voice assistants like Alexa and Siri. There is also a traditional key option for emergencies.
The U400 lock is built on the Thread protocol, which means it can work with many smart home systems. These include Alexa, Apple Home, Google Home, Home Assistant, and SmartThings. It does not need a special hub from Aqara, which makes it easier to use with different brands and devices. The lock is also Aliro-ready, which means it is designed to support digital keys from various providers. For example, support for Samsung Wallet is coming in early 2026, making it possible for Samsung users to use their phones as digital keys too.
Security is a major part of the U400’s design. The use of UWB makes it harder for someone to trick the lock with relay attacks, which are a known risk for other wireless locks. The lock uses features like a scrambled timestamp sequence to protect against these attacks. Other features include auto-lock, which uses a built-in gyroscope, and an IP65 rating for weather resistance. The lock comes with a rechargeable battery that can last up to six months per charge. If the battery runs out, it can be recharged with a standard power bank.
The Smart Lock U400 is available in four different finishes, including black, silver, shadow black, and satin nickel. It is being sold through Aqara’s website, Amazon, Apple Store locations and online, Best Buy, and other select stores in the countries where it is being launched. The lock is also on display at CES 2026, where Aqara is showing a live demo. The U400 uses secure technology from NXP Semiconductors for both UWB and NFC features, and is also part of NXP’s showcase at the event.
More information about the Smart Lock U400, including purchasing options and technical details, can be found on the Aqara website. The company is positioning this lock as a step forward in making home access more secure and easier to use for people who want to integrate smart technology into their daily lives.
View the original press release.
