The Marvin Signature™ Ultimate Bi-Fold Door opens a home to true indoor/outdoor living, with panels that fold open and closed like an accordion. Because weather and the seasons don’t always beg for a wide-open expanse, choose a configuration with a single swinging access door allowing for quick and convenient everyday operation. When it’s time to open up the room and let views and fresh air in, expansive widths of up to 55 feet make the Ultimate Bi-Fold Door one of the largest folding doors in the industry. Sill options allow you to adapt the door to required performance levels based on environmental exposure. Choose the Performance Sill when the door exists directly to the exterior. For sheltered exposure, a Low Profile sill may be appropriate. For interior applications, select the Floor Channel as a room divider.