The BlocOut™ Blackout System. The Award winning Bloc Cassetted blackout blind allows you to create bedroom darkness for high-quality sleep, day or night, whatever the season. Blocout Touch fits windows up to 1800mm wide, whilst the Bloc Plus 80 covers windows 2400mm wide. Side rails along with the top cassette, prevent light from escaping along the edges; a bottom seal creates a barrier between the bottom of the blind and the window sill, blocking out light and reducing heat loss.