This card holder is a prototype (meaning it was used to experiment with techniques/size/shape etc) and thus was made of a faux-leather/vinyl. The faux-leather has natural wrinkles done in manufacturing to make it look like leather. It may have some pen marks for measurements on the inside. It has a brass screw-back button stud closure and is unlined. It will fit all credit cards, folded bills, and perfectly fits your Covid-19 Vaccine Card.
Size: Approx. 4.5 x 3.25 inches (flat)