Dual outlet-type BOV. Dual Port vents both to the atmosphere and back into the air intake. Ports with sequential timing allow quieter operation during normal driving, while getting all the benefits of a vent-to-atmosphere BOV under race conditions. Easily converted to a full atmospheric or full bypass unit by using supplied port blanking plug. Fits most cars using the factory BOSCH or DENSO bypass valves, also Subaru Legacy/Liberty 09-10. Available with either 20mm, 25mm or 34mm inlet port (please specify when ordering)