DOUBLE LOCK DESIGN: Sliding window locks utilizes double screws to mount on sliding windowdoor tracks, prevent sliding and add more . Simply screw them with hex keys (included) for fully windowsdoors or to allow for ventilation, no extra tools needed. Comes with rubber cushioning to prevent scratches or damage to the window and improve window . COMPATIBILITY HOW TO USE: Window locks are applicable for sliding windows, sliding doors and vertical doors. Locks are 2.4 inches long and fit tracks up to 0.4 inches wide inches with rubber cushioning or up to 0.67 inches without rubber cushioning. Please measure your track to ensure proper fitment. HIGH QUALITY: The window lock is made of aluminum alloy, durable and sturdy. The anti-rust coating makes it a good match for white sliding windows, sliding doors and vertical doors. USEFUL SITUATION: Slider window locks are perfect for sliding patio doors, sliding glass doors, etc. Feel to open the windows a few inches to get both fresh air and peace of mind, because they no longer open enough for someone to slip into your house without breaking the window and alerting your dogs. Put some window lock latch to your kid's room to keep your toddler from falling out the windows. PACKAGE INFORMATION: Pack of 4 sliding window locks with rubber cushioning and keys; Apply multiple window locks can increase sliding doorwindow .