Having experienced many disappointing tries and failures on finding me a case - Bumper, Flipcase, Bookstyle, whateverDoesTheJob - for my FP2 AND FP3 respectively, and wasting lots of time, resources and money ordering them and sending them back right away, I’d like to share my wisdome. And -hopefully - save others the same tedious procedure.
Watch out: Googling (or ebay-search oder amazon-search) “fairphone 3 case” or “fairphone 3 bumper” will get you lots of results, but most, if not all of these cases that are classified “fitting FPx” are actually standard cases made for mainstream phones and not particularely for the FP. So most of them are too small, too short or simply not fitting the height of the FP3. Most of the vendors do not give exact dimensions - for good reason!
To seize the protective effect, the case must protrude the phone in each dimension and most do not.
In particular the vendor K-S-Trade (via ebay and via Amazon) as well as the shop gsm55.de offers quite many cases explicitely tagged as FP2 or FP3 compatible, but they are NOT.
I know, for I tried. And failed.
See my photos on that …