hm.. I've seen those at shows. However, for me, I wouldn't keep juvies in anything less than 1/2g. For 2 bucks each, you might as well buy 1+ gal tupperware containers that stack easily and are much roomier. I dont like that those are soooo tall, because the Bettas have hardly any room to stretch their fins
I DEFINITELY wouldn't put HM or full Delta juvies in there, they need much much more space to get nice full tails.