ADJUSTABLE WINDOW GAP SIZE: The SAFELON Window Restrictor offers two window opening settings: 3.62" (9.2cm) and 5.31" (13.5cm). This adjustable gap meets daily ventilation needs while accommodating a variety of user requirements. Material: Constructed from durable polyamide, the window lock is designed for strength and reliability. It helps prevent accidents such as children or pets accidentally opening windows, finger pinching, or falling through open windows. Suitable for households with young children or pets. Easy Lock and Unlock: Equipped with a double-button release mechanism, allowing adults to easily unlock and operate the window. The design features no keys or removable parts to lose. Adjust the window opening by pressing and holding the slider button on the rod, then pushing or pulling the window into position. Simple for adults to use, difficult for young children to operate. EASY INSTALLATION AND TIPS: SAFELON window stoppers include both adhesive tape and screws to support secure installation. Follow included instructions for proper mounting and optimal performance.