Enables you to keep the pcv valves without getting actual oil in the intake. As for venting to air this would eliminate the mist but you cannot do that on our cars. The only air that can vent from our engines is from the end of the exhaust pipes and the only air that is allowed to enter is from the air filter. Your only choice is an inline catch can.
"torque gets you off the line...& hp gets you over the line." - TTKeeper