They were an Amazon purchase: https://www.amazon.com/Aybloom-Small-Plastic-Storage-Containers/dp/B085ZGTF51/ref=mp_s_a_1_3?dchild=1&keywords=Aybloom%2B30%2BPack%2BSmall%2BPlastic%2BBeads%2BStorage&qid=1601037020&sr=8-3&th=1&psc=1

For best fit, if you order, be sure to select the 2.5x2.5x.08 option (30 for $16.99)

Here’s what they look like packed away in the box: https://imgur.com/gallery/189vC3q