https://www.amazon.com/Vaultz-Locking-Supply-Tactical-VZ00192/dp/B00KWN5VZ4/ref=mp_s_a_1_4?dchild=1&keywords=vaultz+lock+box&qid=1618436798&sprefix=vaultz+loc&sr=8-4

This is what I use. I get 2 weeks worth. I just leave the box sitting up on its side. It will fit 2 rows of 7 easy. They're at Walmart in school section or electronics area. Technically used for cds. But the cd holding flaps come right out. Cheaper at Walmart then online.

Also these are the perfect size for volca:

https://www.amazon.com/Vaultz-Locking-Supply-Tactical-VZ00192/dp/B00KWN5VZ4/ref=mp_s_a_1_6?keywords=vaultz+lock+box&qid=1573026601&sr=8-6