Install at least 9 cm away from the frame as shown in the photo. For slot width selection: if the slot is greater than 13 mm, choose the S model; if it is less than 15.5 mm, choose the L model. Key features Material and design: Made from stainless steel for durability and corrosion resistance; detachable design for flexible use and easy maintenance. Functionality: A window stopper that limits how far a window can open. Compatibility and performance: Designed for most standard window frames and slot widths; smooth, reliable operation and simple installation. What it delivers Keeps spaces secure while allowing natural light and fresh air. Provides a stable, lasting hold. Use scenarios Home safety: Prevent accidental openings when children or pets are nearby, at bedrooms or play areas. Ventilation without compromising security: Crack windows in living rooms or offices to improve airflow while maintaining a barrier. Temporary or rental use: Secure windows during occupancy changes or in shared spaces.