1)Gas Spring Metal Ball Socket Ends 2)ISO9001:2000 3)Centres: 24-30, 20-30, 18-20, 16-20, 15-18, etc. Gas Spring Metal Ball Socket EndsCentres: 24-30, 20-30, 18-20, 16-20, 15-18Threads: M6, M8, etcMaterial: Steel, stainless steel, iron, etcFinish: Nickel Plated, zinc plated, etcEasy assemblyISO9001: 2000 Welcome customers home and abroad to cooperate with us.