Page request
In the Fairphone install pages users are drawn to the red printed Caution box
Users really should read the whole document and understand it before install. Perhaps the installer should include
I read and understood the hazard associated with anti-rollback and a 
to move on.
Meanwhile users can find the full document in the install page
- Install /e/OS on a Fairphone The Fairphone (Gen. 6) - “FP6”
- Install /e/OS on a Fairphone FP5 - “FP5”
- Install /e/OS on a Fairphone FP4 - “FP4”
- Install /e/OS on a Fairphone FP3/3+ - “FP3”
To check the Android security patch level on your phone with a locked bootloader open your phone
Settings » About Phone » Android Version » Android Security Patch Level .
Hint before Install Please take the time to take a screenshot of, or write down, your Android SPL
Compare it against the level of the security patch on the /e/OS build as visible in the Downloads section of the above linked pages.