Some time ago I dropped the key to my Citroën C-zero and as the key hit the ground, one corner was damaged. The next time I used the key in the ignition, it fell apart, and I lost one of the two button "shields".
Kind of annoying, but not the end of the world, I removed the other button shield, taped the key case together and everything worked. But exposing the rubber-buttons to the elements might not be a great idea, and it doesn't look so nice.
Finding the correct replacement was not that easy, as none of the sellers of key cases seem to list the Citroën C-zero as a matching model, but I finally found this product on AliExpress: KEYYOU Flip Car Key Case For Peugeot 4007 ET 4008 For Citroen C-Crosser C4 Aircross Replacement 2 Button Remote Key Shell MIT11R.
It took almost 5 weeks to arrive from China, but it's the right one!
It was a little tricky moving over the metal part of the key (getting the spring right), but I succeeded at last, and now it looks nice and seems to be exactly the same as the old broken shell. Recommended!