The security lock Window Restrictor is designed to limit the opening distance of windows and doors to help reduce the risk of injury from falls. Suitable for most casement, wooden, PVC and aluminum windows and sliding windows (horizontal or vertical). Safe: Prevent children from pinching their hands by opening and closing windows/doors without adult supervision; Prevent babies/children from accidentally falling out of windows or going out of doors. It is not only effective for children, but also for pets. Our window restrictors are adjustable and can protect children while fulfilling the ventilation function. There are two different opening sizes to choose from: 5.12 inches (13 cm) and 6.30 inches (16 cm). Simply change the circular knob and adjust the door spacing to your liking. Window Restrictor Locks: These window limiter locks come with strong adhesive, They can be fixed firmly without drilling. All you need to do is peel off the protective film from the lock and it can be directly attached to the windows or doors (the effect will be better after 24 hours). Meanwhile, it is easy to remove with a hair dryer and will not damage the window surface.