It was Arthur C. Clark who said, “Any sufficiently advanced technology is indistinguishable from magic.”

I think about that saying whenever I run across a gadget that really impresses me with a particular feature.

For the last month or so, I’ve been testing the Eufy FamiLock S3 Max smart lock for my front door. The Familock S3 Max ($399.99, eufy.com) is one of the new smart locks from Eufy that utilizes palm vein unlocking, which is just magical when you use it.

When I walk up to my front door, I hold out my palm about four inches above the lock for about one second, then by the time I reach down to turn the knob, the door is open.

Eufy says palm vein reading is much more accurate and easier to use than using a fingerprint sensor. I believe it.

The S3 Max also can unlock by entering a code on the keypad or through the Eufy app on your smartphone. Lastly, it does come with an actual key you can use to unlock the door.

This lock also works with most smart home automation systems including Apple Home, Google Home, Alexa and SmartThings. It also supports Matter.

The S3 Max is powered by a 15,000 milliamp-hour rechargeable battery, which can power the lock for several months. The main battery can recharge via USB-C in just a few hours but it has to come out of the lock to recharge. To cover the time when you’re recharging, the S3 Max also has four AAA batteries to let you open the door via your code, but it disables some power-hungry features like palm vein unlock and Wi-Fi.

But the S3 is more than a really cool smart lock.

If you look at it, you’ll notice it has a camera, and a big button at the bottom that’s also a doorbell.

If someone presses the doorbell, you’ll get a notification on your phone and you can use the Eufy app to see and speak to the person at the door. The camera shows a head to toe view of the area outside the door with 2K resolution.

But wait … there’s more.

The portion of the lock on the inside of your door has a 4-inch video screen to show you the live view of what’s on the outside. The screen powers on if the doorbell is pressed, or you can turn it on manually. This is great for people who are not tall enough to look through the peep hole.

You can also call up the camera’s view from your phone.

Like other doorbell cameras and security cameras, the S3 Max’s camera can send you notifications if it senses motion. The lock can also send you notifications when the door is opened or closed.

One of the features my wife and I like best is the ability of the S3 Max to know when the door is closed and to automatically lock itself after a set amount of time.

We set it to lock within 10 seconds after closing and it was so nice to be able to close the door and walk away knowing it would lock itself.

The palm vein reader is very simple to set up. In the app you add users, set them up with a 4- to 8-digit passcode and then you can read their palms. When the app tells you, just hold your open palm about four inches above the sensor and your unique vein pattern will be registered in just a few seconds. You register both palms, and the vein recognition works even as you age or if your hands are wet or dirty.

The app can keep track of up to 50 users.

You might not realize it, but doors with fingerprint readers have a tough time registering and reading the fingerprints of older people. The S3 Max has no such limitation. Fingerprint readers also have trouble if your fingers are wet or sweaty.

Palm vein recognition worked perfectly -- every time.

The S3 Max, because of the doorbell and camera, is designed for doors without a screen door or storm door.

If you do have a screen door or if you already have a video doorbell and you don’t have a need for the video screen, Eufy does make other models of smart locks with palm vein recognition without those features.

I also tested the FamiLock E34 ($279.95), which does not have a camera, doorbell or video screen and it is perfect if you have a screen door.

The E34 has the same palm vein unlocking and keypad, as well as physical keys and opening it by holding out your palm is just as magical.

One big functionality difference between the E34 and the S3 Max is how it handles auto locking.

The E34 does not have a sensor to know if the door is open or closed, so the auto locking setting is by time only. We set it to automatically lock one minute after it unlocks, which usually gives us time to open the door, get out and close the door before it locks itself.

On both smart locks, you can press the small shield icon at the bottom right corner of the keypad to immediately lock the door.

Conclusions

I think everyone could benefit from a smart lock for their doors. I can’t remember the last time I had to use a key to get into my front door.

Each new generation of smart locks brings new conveniences, and the palm vein unlocking is what should get your attention.

I thought fingerprint readers would be the big thing, but I can’t tell you how often my wife had to repeatedly press her finger on our previous smart lock. There were many swear words. It worked fine for me, but not her.

She and I are 100 percent happy with the S3 Max and the E34. Palm vein recognition is indeed magic.

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