Handwritten in ink on hub of disk behind metal door.
overall: 3/8 in x 5 3/8 in x 6 in
Optical disk cartridge consists of a rectangular cartridge with a metal strip wrapping around the middle front and back. There is an embossed "A" on one side and "B" on the other side. There are red tabs inside the lower corners visible through holes and a black dot in the lower middle of the "B" side.