Check the listing for details. Mac Valve (Holley CO2 Boost Control Solenoid) 90 degree Mounting Bracket. Condition: New. Listed at 35.98 USD. Mac Valve (Holley Boost Control Solenoid) 90 degree Mounting BracketRunning a dual solenoid boost control setup is becoming the standard across EFI systems, and boost controllers. However, there is always confusion on plumbing and mounting. It is always a pain sourcing fittings and making bracketry. We decided to make it easy with this bracketry setup. This setup allows you to mount using bolts through sheet metal/brackets, or clamp to a chassis bar. Connects solid with a T, and gives inlet and outlet possibilities. WE thought of everything with this. Included:Black Anodized Bracket 90 degreeHardware2 bar clampsNickel plated T with 1/8NPT female outletOptional Solenoids (These are the exact solenoids Holley and other manufacturers use, just without their label). For full plumbing questions, reference the attached diagram (in pictures).