Jooste Cylinder Ring Set As150 Includes A Spring Plunger Valve And A Blue Polyurethane Ring. The Polyurethane Ring Is Designed To Create A Watertight Seal In The Piston Preventing Water From Passing Through On Each Stroke. This Ensures Optimal Performance And Efficiency For The Piston System. The Set Is Specifically Designed For Use With Jooste Piston Based Machinery Contributing To Smooth And Reliable Operation. Its Durable Construction Helps Reduce Wear And Tear Over Time Extending The Lifespan Of The Piston System. The High Quality Materials Provide Enhanced Resistance To Wear Ensuring Consistent Functionality Even Under Demanding Conditions.