... 2Cycling test:50,000times 3Smooth and noiseless 4Reasonable in price Concealed slide SWT663BLH Productconcealed slide SWT663BLHItem numberSWT663BLHMaterialGalvanized sheetSize300mm,350mm,400mm,450mm ... can pass 50000cycles test, surface can pass 48hours salt spray. Concealed drawer slide(SWT663BLH)