These window guards meet New York City Department of Health regulations and measure 15" high with 4 3/4" between the bars. They mount in the frame beneath the upper window panel. Made of heavy-duty steel with non-toxic baked enamel finish. Fits double-hung windows from 14" to 24" wide. This is a non-opening window guard and is not suitable for sleeping areas where a quick exit may be required. It is designed for exterior use and does not have the same quality finish as our Deluxe Guardian Angel Window Guards.