With all the e-shop, Virtual Console, WiiWare, and Project M covers for SD Cards and USB sticks in 3DS cases, I thought this might be useful to someone:


These can be for storing your Retron 5 SD cards when not in use, or if you want one specifically for backed-up save games or screenshots or whatever. Plus you never know if the community might hack the system to do more via SD cards.
Unfortunately I had a really hard time finding a high quality pic of the black version at a good angle, so it's a little pixelated. If I find a better pic, I'll update it.