1.igh precision , lower noise 2.have passed ISO9000 3.short delivery,near port 4.high speed operation and long durability Ball Screw Features:1.C5-C7 Grade precision2. Good performance with low noise3. Soon delivery4. Nice appearance5.Friendly serviceSFE ,DFU,SFT ,SCI ,DFT,DFS,DFV,SFI,SFK ,SFU Series and special ball screws ! China plastic lead screw have passed ISO9000