BOV boost pressure relief valve kit AWESOME SOUND EFFECT !!! Protects your turbo !!! Kit designed for DIESEL engines. Contains: Pressure relief valve with working pressure over 2.5 BAR Solenoid Controller Power lines Vacuum line High quality workmanship. Mounting hole diameter: 25 mm BOV boost pressure relief valve kit. AMAZING SOUND EFFECT !! ! Protects your turbo! Kit designed for DIESEL engines. Includes: Relief valve with working pressure over 2.5 BAR Solenoid Controller Power lines Vacuum line High quality workmanship.