Here's what you have I think , I picked up a few awhile back, They hold 8mm rounds. Very cool original boxes
http://www.ima-usa.com/german-wwii-breda-mg-feed-strips-8mm-in-swastika-marked-chest.html
http://www.ima-usa.com/german-wwii-breda-mg-feed-strips-8mm-in-swastika-marked-chest.html