St. Benedict Prayer for Protection A Shield of Faith BOV Dual Port Uni 32mm Blue. Four BOVs in one. Suits medium sized turbocharger systems on 4 to 6 cylinder engines developing 200 to 600 HP. The Dual Port can be configured as a Supersonic, Megasonic, Plumb Back or Dual Port! Features sequential ports for quiet operation on mild boost and full performance at full boost. With a Quick release V Band clamp, tool free adjustment and all the parts needed for conversions included, it is Turbosmart's most versatile BOV.