1.The window lock is apply for sliding windows, sliding doors and vertical windows.please measure your window track size height must be 0.55inch (1.4cm) and width must be less than 0.59inch (1.5cm) before ordering window locks. window locks is equipped with a vertical key, which can be applied to the middle track of the window. 2. Upgrade protection design,our each window lock has two fixing holes,secure it on the window track,which greatly enhance the holding power of the lock,use double hole locks on heavy windows/doors for added security. window locks are also equipped with protection pads to prevent scratches or damage to your window and improve stability. 3. It ensures your family members safety,can control the window partially open or closed,effectively reduce the risk of children and pets falling from high windows,by locking your windows, it can also protect your property against damage during heavy and .also, it prevent burglars and thieves.This sliding window lock for 4.4No additional installation tools or drilling required,3-step quick installation.step1,place the lock to a suitable position.Step2,Insert gasket protect window track from scratches.Step3,tighten the screws,done you can fix the window lock at any part with the vertical key or hex keys,easy to reuse and re-install. Colour:black Material:aluminum Package Contents: 4 x sliding window locks 4 x hex keys 4 x gaskets 1 x vertical key Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.