Defender Security S 4776 Operable Window Guard, 22 in. - 38 in. x 21 in., Steel, White, 4-Bar, Egress Compliant Inside mounting Assists in preventing children from accidental falls through open windows 3-7/8 in. bar spacing Tamper resistant screws to keep window guard firmly attached See pg. 3 for Hinged Guard Installation Instructions: NOTE: Hinged guards cannot be installed inside frame legs