VWSS(www.vwss.com) is a global, most comprehensive and largest inventory list query system for steel pipes jointly created by Longma and various Chinese steel pipe inventory suppliers. VWSS brings together a large-scale steel pipe stock database. Including API 5L PSL2/ISO3183 PSL2, ASTM A333, ASTM A671/A672/A691 EFW steel pipes, with quantity about 80,000 tons and fastest delivery time of 1 day.