PEX manifold (home-run) system: brass or polymer manifold with individual ports (8-24 ports). Each fixture gets a dedicated PEX line from manifold. Sizes: 3/8 in to fixtures, 1/2 in to bathtub/shower, 3/4-1 in main to manifold. Advantages: fewer connections in wall (reduced leak risk), balanced pressure (no pressure drop when multiple fixtures run), easy fixture shutoff (individual valves at manifold), fast water delivery. Disadvantages: more pipe used, dedicated manifold location needed, cost premium. Manifold: $150-$400. PEX: $0.40-$1.00/ft. Total system cost comparable to trunk-and-branch when labor savings counted. CSI 22 11 19. Expansion vs crimp: expansion (ProPEX) = no inserted fitting, larger flow; crimp = copper ring, universal compatibility.