Walk up to the door with an iPhone in hand and the Aqara Smart Lock U400 opens before your fingers reach the handle. The lock, announced at CES 2026, is one of the first consumer locks built around ultra-wideband ranging paired with Apple's Home Key, a combination that replaces the tap-to-unlock gesture most digital locks still require with something closer to a proximity sensor.
UWB measures both distance and angle far more precisely than Bluetooth, which is what lets the U400 tell the difference between a phone approaching the door and one sitting on a nearby kitchen counter. Aqara says the lock also carries scrambled timestamp sequencing to block relay attacks, the exploit where someone amplifies a phone's signal from a distance to fool a lock into thinking its owner is standing outside. NFC tap, fingerprint, a keypad code, and a physical key back it up for anyone without a compatible iPhone or Apple Watch, and the lock is Matter-certified and Thread-compatible, so it also answers to Alexa, Google Home, SmartThings, or Home Assistant.
"We are excited to be among the first manufacturers to deliver UWB technology in home locks to consumers," said Cathy You, Aqara's senior vice president of global business and strategy. That claim holds up against most of the smart lock market, though not against Apple's own back yard: UWB-based Home Key ranging has existed as a feature since iOS 15, and the real story here is a third-party lock catching up to what Apple's own devices could already do, not a new capability appearing out of nowhere.
The U400 ships in black, silver, shadow black, and satin nickel across the US, Canada, Australia, New Zealand, and Singapore, sold through Aqara's own site, Amazon, Best Buy, and Apple's retail channels. Aqara-branded Samsung Wallet support is planned for later in the quarter, which would extend proximity unlock to Android phones running Samsung's wallet app rather than leaving the feature as an iPhone-only trick.
