The Segal S 4759 Non-Egress Fixed Grids for Windows cannot be opened or quickly removed in case of emergency. For windows requiring emergency access capabilities, please use appropriate hinged version of these window grille inserts. Constructed of 0.048 inch thick, black carbon steel square tubing, this window grid assists in preventing children from accidental falls through open windows. It features 3-7/8 inch bar spacing on center. The grates for windows feature a fully adjustable telescoping width (prior to mounting) from 15-3/4 inch to 22 inch, and it comes complete with one-way, tamper-proof installation screws. Designed for interior use only. This window security grate meets New York City and New Jersey’s housing codes, and it was approved by the New York City Department of Health and Mental Hygiene, HDWG #04-09-2010. Please refer to the line art drawing for dimensions and compare with your needs before purchasing.