Are you looking for a nice and inexpensive case to protect your new GS? I’ve found one originally made for portable 2.5" HDDs (GS needs approx. 95 x 135 x 30 mm). They come in a wide variety of colors & materials… 
BTW: Mine is a bit sturdier, red (like my GS) and holds my GS + a 5000mAH Powerbank + cable (for just a few bucks in a consumer electronics store).
I found out my Nintendo 3DS XL case also perfectly fits the GS!
I think you mean 3.5".
Anyone got any links to compatible cases? I bought a Gameboy Color case, but it barely fits.
Nope, it was marked as being for 2,5" HDD… It measures 100 x 140 x 40 mm (good fit), but I tried in a shop.
A quick search on Amazon shows several cases with the same measures (+ smaller ones, so either look for the right numbers or just go look in a shop)
That may have been how it was marked, but those are the dimensions of a 3.5" drive.
Those may be the dimensions of a 3,5" drive, but not a portable 3,5" drive with shell/casing. Yes, there are smaller cases/bags available for 2,5" portable drives, but if you look on Amazon you can easily find some with the right measures (the smaller ones are for the drive alone, bigger ones are for two drives or with cables or a powerbank etc.).
(I looked in a consumer electronics store, so I could try and test if it fits.)
