Firstly it looks really well made, and is very easy to attach securely to the car seat. The description says it's for 12.3 inch devices, but that's like a tv screen measurement, the “unfold” size of 200mm is the width of the device which it will actually fit. It also won't hold your tablet if you have a case on it (unless it's really thin). I have a bulky wallet-phone case, which was also too thick for it, but I think it would fit most phones with normal cases without much trouble.