1. X-ring (also known as a star ring) is a sealing ring with four lips.
2. Extruded sealing rings with other cross-sectional shapes: ① D-shaped ring ② ordinary triangular cross-section ring ③ star shaped ring.
3 encapsulated O-ring: The so-called encapsulated O-ring is a material that wraps the O-ring around it, making it have the characteristics of two different materials.