Synapse Engineering Synchronic SB001A Blow Off Valve - P/N: SB001A Product Model: SYN- SB001A SB001 is a universal, pull-type B.O.V. design that eliminates leaking by seating the valve more as boost pressure increases. Each assembly is pressure tested to 100 psi prior to leaving the factory. Interchangeable inlet and discharge flanges allow us to offer various adapter and kits for many popular applications. NOTE: Does not include adapter flange.