The Piston Expander Ring fits into grooves on the piston. The purpose is to create a tight seal between the piston and the cylinder barrel, preventing hydraulic fluid from leaking past the piston, and maintaining the pressure required to generate force and extend or retract the cylinder. It is made of rubber material.Attributes:• Has low friction properties, reducing wear and tear on mating surfaces• Withstands the temperatures and pressures encountered during the operationApplications:The Piston Expander Ring is placed on the piston's outer diameter within the hydraulic cylinder. It experiences radial pressure against the cylinder bore, creating a tight seal that prevents fluid leakage.