The cylinder head plug is installed in the fluid end studded assy, which atcs as a fixing function,Heat-treated and internally hardened for high durability; available in various materials to meet a wide range of applications; standard one-and/or-two-piece configuration, with designs available for pressure of 5000psi(35.1Mpa), 7500psi(52.7Mpa), and 10000psi(70.3Mpa); discharge connections available on each side; suction connections on each side or front center. Products Advantage: 1.100% interchangeable with OEM 2.Premium forged alloy steel 3.Made on CNC boring mills 4.Strict computer controlled heat treat procedures 5. Rigid inspection The cylinder head plug is installed in the fluid end studded assy, which atcs as a fixing function,Heat-treated and internally hardened for high durability; available in various materials to meet a wide range of applications; standard one-and/or-two-piece configuration, with designs available for pressure of 5000psi(35.1Mpa), 7500psi(52.7Mpa), and 10000psi(70.3Mpa); discharge connections available on each side; suction connections on each side or front center. Products Advantage: 1.100% interchangeable with OEM 2.Premium forged alloy steel 3.Made on CNC boring mills 4.Strict computer controlled heat treat procedures 5. Rigid inspection