Child Safety Window Restrictor, Adjustable Window Opening, Childproof Window Lock for Children and Pets, Easy to Install and Use (2 Pcs, Grey). Adjustable Window Opening --- The window restrictor allows two different window opening sizes to be selected: 9.2 cm and 13.5 cm. The adjustable window opening can meet daily ventilation requirements and more customer needs. Why it is necessary --- The window lock is strong enough because it is made of polyamide material. Don't hesitate, it can prevent children from playing with windows and pinching their fingers; prevent children from falling out of windows, etc. Not only for babies but also for pets. Easy to unlock --- Press the double button to unlock the lock and the window can be opened or closed freely. No keys or other parts are missing with the lock installed. Adjust the window opening by long pressing the sliding button on the bar and sliding or pulling the window. Easy for adults to use but difficult for babies. Simple installation tips --- The window restrictor provides tape and screws for customers to install. With the tape, it can carry less than 26 kg (the effect will be better after 24 hours). Choose the appropriate installation method based on actual requirements. Wide range of applications --- Used for inward and outward opening windows. Fits most windows on the market.