This EH series is interchangeable with STUCCHI A-HD SERIES, PARKER FEM SERIES, FASTER 3FFH SERIES, VOSWINKEL FH SERIES, VOSWINKEL FF SERIES, and VOSWINKEL FU SERIES. Steel Product. These ISO 16028-compliant flat face couplings are engineered for demanding hydraulic applications, featuring a robust 35 MPa (5076 psi) working pressure rating and durable zinc-nickel plating for superior corrosion resistance. The innovative design allows safe connection under residual pressure conditions with multiple configuration options.