... body gearbox 5)Belt and gear drive JS-550 2 discs concrete grinder and polisher- top seller We JS manufacture medium- ... on surfaces coveringconcrete,epoxy,stone,marble,granite,terrazzo,etc.2,A concrete grinder and polisher s for old floor removal,restoration,renovation ... ratio among all four heads machines made in China.2,A concrete grinder and polisher furnished with JS third generation magnetic plates ...