- Insert Thrust ball bearing; - "Inner stop" technology; - Meet GS standards; - Applying Damping ring Works the part of a person waist and hip Service sitesLuxury Villas Garden, City park, Seaside retreat, Scenic spot, Amusement park, playground, recreation ground, residential park, uptown park, leisure place, community center, activity center, hospital square, school, factoryactivity center, ...