Stacking blocks mount on the center block of Fluidhaus power units for the purpose of adding additional valves to the circuit. The result is a compact system with less hoses and fittings. Each block order (whether 1, 2, 3 or 4) comes with the transition plate and mounting bolts to mount to the center block. The valves are ordered separately per you requirements.
Each block has an A and B port that is SAE -6 Oring boss straight thread ports.