May be several items: Double hung draperies (two sets of draperies usually sheer fabric under opaque fabric, both operating independently).
A double hung window has two moveable sashes and an outside screen. The sash will slide up and down for ventilation. Double hung windows are usually taller than they are wide.
Double Hung windows have two movable sash which operate vertically.
Consists of a pair of vertical sliding sash, either sash opening independently of the other. Older type double hung sash operate through a system of weights, springs, or pulleys.
A window with two vertical operating sash that slide up and down.
referring to a window with two vertical sliding sashes, one over the other. (IMAGE)
A window type comprised of two vertically operating sashes.
A window that both the upper and lower window sashes move up and down.