... test:50,000times 3Smooth and noiseless 4Material: Galvanized sheet Concealed slide SWT663BTH Productconcealed slide SWT663BTHItem numberSWT663BTHMaterialGalvanized sheetSize300mm,350mm,400mm,450mm,500mm,550mmThickness1.8x1 ... can pass 50000cycles test, surface can pass 48hours salt spray. Concealed slide(SWT663BTH)