The system consists of a single metal box that can house two doors sliding in opposite directions. The single central box provides access to two adjacent rooms, with a total opening space that is double that occupied. It is the ideal solution for two adjacent rooms like two bedrooms or a bathroom and a bedroom, and is also particularly suitable for providing access to two separate bathroom areas, for example in public venues. Available only for masonry walls. Also available in non-standard sizes, in heights varying to the nearest centimetre.