That is nice!
But I prefer get few 128 GB instead of 400 GB. I already bought 3 x 128 GB for 20 dollars each, total 60 dollars for 3 x 128 GB last week - early black Friday. I would buy few 128 GB cards again when it on 20 dollars.
400 GB for 80 dollars
4 x 128 GB = 512 GB for 80 dollars (I recommend this over 400 GB for right now)
See different math? I would stick with few 128 GB cards because it beat 400 GB price and give us more few extra storage capacity than 400 GB.
But Bestbuy limited us to buy 3 cards at one time. But we can order again another week or few weeks.
I had 16 x 128 GB (Total 2048 GB equal to 2 TB) microSD (all are bought from Bestbuy every years) I gave one to my sister for her Android to extend storage for bigger files to store on it. My goal to hit around between 100 TB - 200 TB in the future. I love to have many 128 GB cards because of cheap price!
It should work on New Nintendo 3DS XL, Gateway 3DS, Sky3DS, CFW, Nintendo Switch, Pi raspberry, Android and future new hardware to support for new files to store on them.
Cheers