3DS and SD Cards...

[Kosheh]

You should be OK. Kingston's a pretty dang good brand and as long as it's in the adapter, it shouldn't be a problem. You'll still have to transfer data over to a New 3DS if you ever decide to upgrade, though because of the ridiculous intricacies of the filesystem :/
(in other words, you can't simply take the microSD+adapter card out of your 3DS, take it out of the adapter, pop it into a "New" 3DS and expect it to work)