I purchase these in bulk from the post office, so there's no contact with a large number of people. These are specifically for Yu-Packet Plus. They are 7cm thick, so you can pack things like fruit. Made of cardboard, so they are sturdy. This material is recyclable. Size: 24cm x 17cm x 7cm, under 2kg They will be shipped in a宅配ビニール袋 (delivery vinyl bag).