Size: approx 8.3 cm This window accessory prevents children from opening windows unauthorized and climbing out, enhancing safety in the home and other settings. The opening size can be adjusted to limit how wide the window can open, which helps prevent strong wind intrusion while still allowing air to circulate. Key benefits - Safe and simple child protection without blocking ventilation - Adjustable opening for flexible safety and comfort - Suitable for multiple environments where safety and airflow are needed Ideal applications - Family apartments on upper floors, keeping children safe while maintaining fresh air - Hotel rooms and guest accommodations that accommodate families - Schools, classrooms, nurseries, and childcare centers to control window opening and ensure ventilation Performance notes - Maintains continuous air flow while restricting window opening - Easy to install and adjust for different window sizes and safety needs