Fold-slide doors and windows span the entire width of a room, opening up a living space to the outdoors. Due to their accordion style fold up, the panels are moved entirely out of sight, enhancing beautiful views. 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 (ROTO NT). 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. High energy efficiency due to triple overlay sash construction ide selection of handle styles and finishes to satisfy every taste and preference. Full range of glazing options (standard glass: 1" overall). Custom sizes and custom designs, including tall sizes. Made from laminated solid vertical grain Douglas-Fir or a wood of your choice.