GUOXING Strong Alloy ConstructionThe sash jammers are made of high-quality aluminum alloy, durable,not easy to wear.White Powder Coated Finish,a good match with your windows and doors.Reinforcement DesignThe back of the lock is designed with a screw-reinforced anti-pinch arm, so that the base and the lock arm are tightly integrated, which is more durable, avoids loosening, and provides your kids and pets with more security.Give you a sense of securityEasy to Install: Simple installation within minutesjust twist the interference arm to lock or release the window sash, fully ensuring safety.Wide Usage: These multifunctional sash jammers are suitable for doors and windows that open inward and outward, such as room doors, windows, bathroom doors or balcony windows,etc.Also a great security device for motorhome,just to exploreYou will Get4 PCS come with suffient corresponding fixing screws , knock on cover caps and so on. Providing additional security for your UPVC/PVC Doors or Windows.Sash Window Locks for upvc Windows 4 Pcs Sash Jammers Window Security Locks PVC Door Lock Door Jammer Letterbox Lock Casement Home Extra Security -White