{% include alerts/danger.html content="The FP4 comes with an anti-rollback feature. Google Android anti-roll back feature is supposedly a way to ensure you are running the latest software version, including the latest security patches.
<br><br>If you try installing a version of /e/OS based on a previous AOSP core version than the one running on your phone, or based on a security patch that is older than the one on your device, you will brick your device.
<br><br>If you try installing a version of /e/OS based on a security patch that is older than the one on your device, you will brick your device.
<br><br>To check the security patch level on your phone with a locked bootloader, prior to installing /e/OS, open your phone `Settings` >> `About Phone` >> `Android Version` >> `Android Security Patch Level`.Then compare it against the level of the security patch on the /e/OS build as visible in the Downloads for the FP4 section below.
