EASY INSTALLATION: No need to install any additional tools, it comes with a hex key in each window lock, which is fixed to the rail by the key control. DURABLE MATERIALS: strong, sturdy and fine workmanship, a aluminum alloy frame and stainless steel screws, can be fully used again and again. Versatile: can be easily applied to most environments, keeping windows partially open and closed, burglars and thieves can prevent children from falling, improving air circulation while protecting your family. Package: 1 door and window stopper Size: 30x24.5mm Material: Aluminum alloy and stainless steel Note: Due to the different images displayed, the actual color shall prevail. Dimensions are measured by hand, there may be errors (1-2cm). Product name: aluminum alloy door frame security lock for sliding window