3500-4000 children fall out of windows every year, many of them second story windows, with tragic results. The Little Tot Window Opening Control Device protects young children by limiting the window opening to less that 4 inches (an ASTM standard), and by including an emergency egress feature which allows the window to be opened fully by an adult in the case of fire or other emergency. They are available as an option on new Mercer 800 series windows, both single hung and slider windows.