"F F STORAGE 5" is engraved on a black label at the front of the object. There are 32 lights (16 red and 16 white). "M.I.T. DIGITAL COMPUTER LAB." is written in white on the front of the unit. At the back there is an 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 3G".