Scope of application: hydraulic reciprocating motion system. Under high pressure conditions, the heavy-duty two-way piston seal is excellent. It is especially suitable for long stroke and wide range of fluids and high temperature occasions, and can be used for large piston clearance. Cylinder piston seals mainly used in heavy load or construction machinery have good leak control, extrusion resistance and wear resistance, such as excavators, heavy hydraulic cylinders, etc.