I hope somebody knows what size to buy. I have been wondering the same thing. Also, when to put the bands on. I don't want to have to remove bands from a growing chick and replace with larger bands. Once the legs stop growing I'd like to put bands on the birds. I'd rather run multiple brooders even than deal with removing leg bands from growing chicks.Are we all using leg bands? I dunno what size to buy? Maybe finch equivalent would do!