AGS is terrific Aluminum door and window company in Massachusetts. They produce products mostly for commercial applications, yet their bifold and sliding doors can be used in residential situations quite nicely and very cost effectively (the best prices I have). This is a non-thermally broken unit and not recommended for climates with extreme cold or hot temperatures. This company prefers to ship product without glass, and have you order and install glass on site. They will give you the needed specifications for the glass supplier. The Plus side of this is less cost in shipping and easier installation handling. The production lead times are also shorter than any other product I supply, on average 5 to 6 weeks, after shop drawing approval.