<p>Ventilation and Adjustment - Our window restrictors are adjustable to protect children while meeting ventilation functions. There are two different opening sizes for you to choose: 3.62 inches (9.2 cm) and 5.31 inches (13.5 cm). By pressing the sliding button on the rod, you can push or pull the window to adjust the window opening size.Why You Need It - Prevent babies' hands from getting caught when opening and closing windows without adult supervision; Prevent babies from climbing windows; Prevent toddlers from accidentally falling out of the window. It is not only effective for babies but also for pets.Universal and Durable --- The window restrictor is made of PA66 + GF20 material, which consists of two parts, strong and durable. Our window locks can be used for both inward and outward opening windows.Installation Tips---Use screws and 3M VHB transparent adhesive to achieve the best installation effect. The 3M VHB transparent adhesive has ultra-strong adhesive power (best effect after 24 hours) and can be easily removed without leaving any traces.EASY TO USE: The window restrictor can be easily unlocked without a key. Press the two buttons on the lock body and push the window to unlock it, allowing the window to open fully as usual. It is easy for adults to use and difficult for babies to open, providing effective protection for babies.</p>