... Roller Shutter Doors are adopt the 55mm, 77mmslat with the PU foam inside it. Detailed description for residential roller door1) Main slat for ... ventilation, energy-saving, trustworthy, convenience etc.3)Installation mode for the roller shutter---mid-side installation, out-side installation, in-side installation.4 ... any color can be adjusted by customers requirements) Double Roller Shutter Doors