the Insulation Interior Roller Shutter Doors are adopt the 55mm, 77mmslat with the PU foam ... ) Main slat for option---55, 77 aluminium extruded slat (roller door) or the steel foam slat.2)Advantages,it is the ... -saving, trustworthy, convenience etc.3)Installation mode for the roller shutter---mid-side installation, out-side installation, in-side installation.4 ...