Product Description: Optimal Security and Ventilation: These window restrictors are designed to provide robust protection against unwanted openings, allowing you to ventilate your home with peace of mind. Perfect for homes with children or pets. Technical Specifications: Durable Material: Made of high-quality metal to ensure increased longevity and resistance to daily wear and tear. Measurement Tolerance: Please note that an error margin of 1-3 cm is possible due to manual measurement. Simplified Installation: Easy Assembly: Installation requires no complex tools; a simple screwdriver is all you need. The product comes with the necessary screws, eliminating the need for a drill. Versatile Use: Wide Compatibility: Perfectly suited for sliding and casement windows, as well as standard plastic, wood, or metal doors. It allows you to lock the window in a slightly open position for safe ventilation. This product is sold by xiaosong on behalf of a third-party seller; it is a compatible product. None of the products offered in this store come with two batteries; they are powered by a single battery. Note: 1. Due to variations in brightness and screen settings, the product color may differ slightly from the images shown. 2. Please allow a measurement error of 1-3 cm due to manual measurement. 3. Please check that the size is suitable before purchasing. Thank you for your understanding!