... .Tolerance:about 0.5mm 3.Material:Galvanized ,aluminum alloy aluminum "U" channel mounting rails1.Cut Length:1 to 6M 2.Tolerance:about ... TRAFFIC SAFETY FACILITIES CO.,LTD.Address (Beijing Office): Room 2305, Block 10, Courtyard 4,Yiyuanju, Cuiwei Road, Haidian District, Beijing ChinaPostcode ... ChenTEL: +86-10-88613215FAX: +86-10-88613214Cell phone:+8613269401318 aluminum "U" channel mounting rails