Dear customer Welcome to our store NANDIYNZHI，The quality of our products is guaranteed and the price is favorable please rest assured to buy!Regarding product information it is recommended that you check the product details first. If you have any questions please consult our customer service. I wish you a happy shopping！ Anti-Theft Child Security Window Lock Child Protection Safety Lock Description： Can fix the window in place and cannot be pulled or opened effectively prevent your child from opening the windows on his own anti-theft and keeping the fresh indoor air. No additional tools are required and no need for drilling. Open the windows to the proper position or close the windows as your need. Adjust the spacing of the window lock and place it on the window frame rotate the above switch to adjust the width to fix the lock. Tighten the switch till the window lock can not move which can make the window lock work efficiently. The clamping distance is between 2.5- 4cm and the groove height is better deeper than 1.5cm for the maximum function of the lock. Its width fits most windows frame but we still suggest you have your window frame measured first. Our anti-theft window locks are made of aluminum alloy durable and thick. And it has non-slip silicone pads to increase the strength. Window locks designed for horizontal sliding windows sliding windows and sliding doors like sliding doors sliding glass doors sliding windows to keep them locked without having to make any change making these a must-have for any parents that want to add more security to their home or office. Package contains: 1PC Window Lock