The housing is made of PPO, high strength, ageing resistant and long life.One-way valve adopts double ball structure, the valve seat is made of PTFE precision machining, more corrosion-resistant. The solenoid is made of pure electrical iron, which is difficult to process and has a greater service force.The junction is made of high temperature resistant enamelled wire from the well-known crystal brand, with a long life span.All components on the PCB board are made of well-known brand, which guarantees higher quality.Dual adjustment design of stroke stiffness and frequency, with diversified flow adjustment options.