The object is a metal panel apparently designed to bolt to a larger object. On the front of the panel are 16 red indicator lights (all are populated) and 16 white indicator lights (all are populated). Printed on the front of the panel are INDICATOR PANEL MOD II and M.I.T. DIGITAL COMPUTER LAB. A plastic label on the bottom front of the unit has "A. C. PARTIAL SUM" engraved on it. On the back of the object are 2 terminal strips. Attached to the terminal strips is a board containing integrated circuits; these attachments obviously postdate the original object. A tag attached to the object reads "Whirlwind Stack 3B".