Designed and rigorously tested for use in hydronic heating and cooling systems, the M-8330 manifold series includes three models. The premium .304 stainless steel 1-inch supply header has built-in flow meters that allow for precise adjustment of the circuit flow rates. The 1-inch return headers have easy to actuate circuit isolation valves. All components have superior EPDM o-rings and seals. Every manifold is loosely assembled onto its mounting bracket ready for immediate installation at the job site. The three models are the M-8330P Stainless Steel Pro, M-8300AP Stainless Steel Pro and M-8300 Basic.