... 17.50mm Detailed Information About the SpringMaterialCarbon steel, alloy steel, stainless steel, spring steel or as ... 15mm-8mmLoad typeExtensionFinish zinc, copper, nickel, black, chrome plating, galvanizing, etc.Advantage High and durable quality, suitable price, ... plastic bag, outer carton box, and advised by customerCertification ISO9001:2008 Products dispaly high quality small double hook tension ...