Parker's Refrigerating Specialties Division offers two types of manifolds for use in conjunction with their full line of Safety Relief Valves. The M1 Inline Manifold comes in sizes ranging from 12" to 1-14" (13mm to 20mm), and it is for use with the SR and SRH Relief Valves. The M2, M3 and M4 Dual Stop Manifolds are for use with Parker's H2, H3, H4 and H5 Relief Valves, and they are available from 34" to 1-14" (20mm to 32mm). All Safety Relief Manifolds are designed to comply with ASHRAE and IIAR standards.