The phone is locked in place by the miraculously strong neodymium magnets and doesn't even budge when you hit a huge pothole or run over a speed bump at 30 MPH

Been using this for about a month now and my phone has never fallen off the magnet even when going through pot holes and speed bumps.

Has been holding tight for an iPhone 6S+ over speed bumps and rough California highways.

I have not had any instances of the phone falling when traveling over rough roads or speed bumps

Speed bumps though, didn't seem to make it budge at all.

The instructions say the preferred usage is inside the case (if one is being used) but when I tried that my heavy OtterBox case was too thick and it would not reliably hold my Samsung S6 in place, especially when going over speed bumps.

I have bought these for all of my phones, as well as my S/O's phones

Use CAUTION before sticking this to anything as the 3M adhesive works well and is hard to remove.

Used this for my Accessport instead of the cheap 3M provided mount