Widely Compatible --- Our window restrictor can be used for inward-opening windows, outward-opening windows, etc. Also suitable for window frames with beveled and rounded edges. Why Need It? --- Prevent babies from opening and closing windows without adult supervision; prevent babies from climbing on windows; prevent toddlers from accidentally falling out of windows. Not only effective for babies, but also for pets. Adjustable and Ventilated --- You have a choice of two different opening lengths, 2.95" (7.5 cm) and 5.31" (12 cm). Press and hold the sliding button on the post to push or pull the window, allowing you to adjust the window opening length. Installation Tips --- The tape (the effect will be better after 24 hours) has strong adhesion, leaving no damage or residue on the window surface. The post of our window lock is stronger than before and can withstand 255N of force. Easy to use: Press both buttons and push on the window to unlock. Close the window to lock it automatically. It is easy for adults to open but difficult for a baby.