Google is rolling out a new feature for certain Android users that allows the phone to automatically lock itself when it is distanced from its owner. It is a bio-metric security feature called “on-body detection” designed to presumably detect data from thieves.

The new detection mode uses the device’s accelerometer to detect whether or not the Android is near a user’s body, according to PC Magazine. If the device discovers that the user is no longer holding it, or that the device is no longer in a pocket, it will lock.

So, if a user sets it down, it locks. This should make it nearly impossible for anyone who does not own the phone to access the data.

If the user chooses to use the on-body detection mode, he or she only needs to unlock the phone once. This means that it will remain unlocked even when it is shifting in a purse or pocket.

This also means that when the phone is immediately passed from the user’s hand to another person’s hand, it will remain unlocked. Although the phone is smart, it is not smart enough to determine which hand it is resting in.

This feature will be available for certain Android 5.0 and up devices. Google has not made any other announcements on who will be able to use the feature or when the feature will be available.

However, Android Police has heard that the feature is appearing on several Nexus devices, including the Nexus 4, along with others. The feature seems to be tied directly to the latest version of Google Play Services (7.0.97), according to Slash Gear.

This is not the first time Google has added smart-locking features to Android. The Android version 5.0 Lollipop had the ability to detect when a near-field-communication tag or a trusted Bluetooth device was nearby and it would automatically disable the security lock.