Look, virtual advent calendars are a dime a dozen right now but our big point of different here at CRANK was that we'd called it CRANKVENT. Ha ha! So witty. So unique! But an alert reader has alertedly alerted us to the fact that crank vents are a THING, a thing which vents the crank case fumes from your Harley Davidson AND controls the air under the pistons by maintaining the proper amount of vacuum in the crank case, at any RPM. It even snaps open for easy cleaning! So annoying. At least we don't spell ours with a K or retail for $124.