By means of Fold-slide doors and windows, a room can be opened up through its entire width to the outdoors, and due to their accordion-style fold-up, the panels can be entirely moved out of sight. Fold-slide opening systems are the ideal choice for opening up a room to the outdoors ("indoor-outdoor living"). Fold-slide doors are comparable to Nana Walls. Key Features: Easy and effortless to operate. For up to 21' wide openings. 22 opening schemes to choose from. Available as top-hung or bottom-hung. High security and energy efficiency, due to fully concealed multi-point locking hardware ( SIGENIA/HTL STAINLESS). Easy installation and smooth operation due to 3-way adjustable sash hardware (up-down + closing pressure + left-right). Solid construction, due to 2 3/8" thick sash and frame, with double mortise-and-tenon joinery. Utmost energy efficiency due to triple overlay sash construction. Wide selection of handle styles and - finishes to satisfy any taste and preference. Handle design can be matched with tilt-turn handles and exterior door handles. Full range of glazing options (standard glass: ¾ overall-DS clear-tempered). Custom sizes and custom designs, including tall sizes. Made from laminated solid vertical grain Douglas-Fir or a wood of your choice.