The 5800 Double Hung window was tested to be used in sizes up to
60"x 99". The air infiltration rate is an amazing .03! This window
features a 4 5/16" frame, block and tackle balances with an
ultra-lift option, 1" insulated glass, and tilt sash operation.
Both sashes operate and automatically lock into position when
closed. Standard options include nail fins, panning, and two