1)fashion appearance 2)rail made of high quality aluminum alloy section bar 3)surface oxidation 4)dull polish processing manual venetian blinds : Manual Venetian blinds have different sizes of 16mm,25mm,35mm,50mm and 90mm and diversified colors. Blinds’ installation, operation, maintenance and cleaning are simple and elegant and have good anti-UV radiation, thermal insulation, dimming functions. ...