The Guardian Angel Window Guards keep tots safe from open windows and window glass, yet can be removed by an adult in case of emergency. Unlike others less expensive window bars, our window guards have a special safety release system featuring two quick-release buttons located on each side. They measure 17 1/4" high with 3 7/8" child-safe spacing between the bars. Mount inside or in front of the window frame. Made of heavy-duty steel with lead-free, white powder coated finish. Available in four adjustable widths to fit double-hung windows from 14" to 120" wide. Meets ASTM standards.