Currency is a relatively new concept for the garou who, through most of their history, relied on a barter system based around hunting. As the Moon Garou settled into less hectic lives, they needed a means of trade that everyone had access to, and so created the chits to do so.
These chits are formed from tiny scraps of adamantite, melted down and then stamped with the branding of the tribes. A fun fact about them is that both sides have garou heads on them, one male and one female, so you can flip as many heads in a row as you want.