BOV Kompact Dual Port Subaru TS-0203-1015Dual outlet type BOV. The Kompact Dual Port vents to the atmosphere and back into the air intake. Ports with sequential timing allow quieter operation during everyday driving while still offering the performance and sound of a vent to atmosphere BOV when the going gets more challenging. The standard blow off valves on these cars are made of plastic, unlike the highly durable machined billet construction of the Kompact. The standard valves are often