Gil
The carton must contain exactly four items. First, the t-shirt, cotton blend, black, size medium. The screen print must be visible through the fabric. Do not wash it. Second, the manual. This document. Third, a single battery, AA, alkaline. Do not remove the cap. Fourth, the key. It is brass. It will fit the lock on the door in your hallway that you have always ignored.
Warning: The t-shirt will become warm if you look at it directly for more than ten seconds. Do not look at it directly.
If the battery is missing, the lock will not open. If the t-shirt is missing, you will remember things you never happened. Check the inventory. Proceed to Step One.