Is there a reason they call it "The Rattler"? Marketing hype? I always wondered if there was some sort of moving counterweight in them or something that made them noisy. It really looks nice.
It's called the rattler because it has a pendulum (or maybe multiple pendulums) in it for balance instead of fluid. When you shut the engine off, you will hear a rattling or clunking sound from it as the pendulum winds down.