Coin (device)
From Just Solve the File Format Problem
Coin (not to be confused with Bitcoin, or actual physical coins) is a device that is the size and shape of a credit card, and can function like one in magnetic card readers, so you can store your actual cards in it and have the device mimic all of them for payments. It syncs with a smartphone to import cards via a card reader you attach to the phone when running its associated app.