These are brightly colored, small metal objects with a serrated edge.

They are encountered amidst other types of waste
matter, but are one of the few potentially useful things in a typical load of
garbage. Each pile of refuse will contain 10-40 Caps, and there is a 25%
chance that someone in the party will risk the ridicule of other members
by collecting them and saving them. One of the most logical possible
uses for Caps is as false currency for bargaining with stupid monsters.
There is a 50% chance that any monster with low intelligence will
believe, for instance, that three Pepsis are worth 100 g.p., and it will be
glad to TRADE so it doesn’t have as many pieces of treasure to guard.