The Eufy FamiLock S3 Max uses palm vein recognition and features a built-in screen to show you who’s at the door.

Eufy's FamiLock S3 Max is the earliest arriving model in a line of video smart locks that shine eyes on the outside.

We’ve seen smart locks that you unlock with a keypad, a phone, or even facial recognition, but Eufy’s latest model—which is actually a video doorbell and a smart lock—serves up a relatively new way of opening your door by scanning your palm.