I borrowed (but quickly turned to stealing
) two Rubbermaid 14oz containers from my wife's pantry. I threw some camo tape over them, paper towel in the bottom, add a call, cut out cardboard top for it bottom call, throw in another call & finish it the lid with another paper towel to keep the calls from banging around. I've been carrying two of them (4 calls) around in my vest for at least 20yrs now.
Whenever I come across the containers I buy them up for my sons to use when they are older. They work awesome