AutoPilot PPM4 Manifold with PPC4 Cell and Base is a pre-assembled unit designed to control flow rate delivered to the chlorine production cell. The spring check valve in the manifold allows excess flow, over 20 gpm, to bypass the cell. The water in turn flows at a controlled rate through the cell where it is chlorinated. The inline strainer on the inlet side of the manifold protects the Tri-Sensor and production cell from debris that might bypass the filter. The location of the strainer next to a connection union makes periodic cleaning easy.