"SS MATRIX" is on an engraved label at the front of the panel. The label is glued on over a previous label with "Parity Aux" visible on the left side. There are 32 lights (16 red and 16 white). At the back there is a add on wire wrapped board with 74LS integrated circuits. Attached to the board is a multi colored ribbon cable. A label attached to the unit reads "Whirlwind Stack 6I".
