Tipping used the annoucement box from Ubu Gallery, New York [The Box: From Duchamp to Horn], to hold an enlarged replicate of an American penny. -- Source of annotation: Marvin or Ruth Sackner.

The letters IOU are engraved and colored with gold leaf on the polished surface of a jagged piece of granite. The edition size is unlimited. The IOU refers to art objects that were paid for and not delivered at the time to the Sackner Archive. These were subsequently delivered. -- Source of annotation: Marvin or Ruth Sackner.