Pretty close. It's a carbon (activated charcoal) canister, just like on all USAspec cars made since the late 70's? It's designed to "soak up" the evaporated vapors from the fuel tank, and it stores those vapors. When you run your engine, the vacuum lines and check valves are designed so that the vapors are ingested into the intake, so the engine actually consumes the vapors. And by doing so, it depletes the vapors in the canister, and "regenerates" the canister for the next time the bike is sitting, so the process can repeat itself. Picture the canister like a sponge that's tuned to soak up petrol vapors...