A device to limit an opening of a window having a hinged sash coupled to a window frame including a window opening limiting structure having a first member and a second member. One of them is securable to the sash and the other of the first member and the second member being securable to the frame. A selectively releasable coupler by which the first member and the second member are couplable is shiftable between a coupled status and a released status. The first member and the second member bridge a preselected distance such that the sash is inhibited from opening beyond a predetermined distance. The coupler is releasable so that the sash can be opened beyond the predetermined distance and re-engages automatically when the sash is closed.