bento container

help with capacity

hello everyone- i'm trying to buy my first "pretty" bento box, and i'd like to do it right so i don't eventually end up with a giant pile of rejects. :) unfortunately, the internets and my location are conspiring against me - there aren't any stores here that sell bento boxes, and all the sellers on amazon have sizes listed in cubic inches. most of the ones i like are 2-tiered by kotobuki or hakoya, and they all seem to be around 5"x4"x3". sooo...if any of you out there have a box that even kinda matches that description, could you pretty please tell me how many mL it holds? thanks!
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Traditional Japanese Bento Boxes & Bento Trays for Sale

Happy Mall has been in business since 1997, selling destination souvenirs and gifts from around the world. Out of our large inventory, one of our main specialties is Japanese traditional bento boxes. Our selection ranges from small to large, simple trays to fancy 3-piece boxes, and are suitable for daily use or special occasions. Most of our bento boxes are made of plastic