Features: High Quality Material: Made of aluminum, it is sturdy and durable. No Punching: Each lock is equipped with a for key, turn the for key slowly through the hole, only need to control with the for key, no additional installation tools are required. Width controllable: Freely control the window width to prevent children or pets from climbing out of the window. Must-Have Items: Secure for windows, prevent children from falling, prevent thieves. Suitable for families, hotels, schools, kindergartens, etc. Package Includes: 4x Window Safety Lock(with for Key) Specifications: Material: Aluminum Style: Single Hole/ Two Holes Single Hole Size: Approx. 24.5x29.5x24mm/0.96x1.16x0.94inch Two Hole Size: Approx. 60x16.5x24mm/2.36x0.65x0.94inch note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.