This high performance VTA (vent to atmosphere) blow-off valve is precision machined out of aircraft grade billet aluminum. It features an internal brass piston design and is pressure tested to withstand up to 70psi, allowing it to compliment even the most aggressive turbo builds. Spring pre-load determines the pressure differential required across the piston before the BOV opens and releases the pressurized intake charge. Designed to be a replacement for the OEM bypass valve. Installation is simple and all mounting hardware is included.