THE PACKAGE INCLUDES-1 window aperture with screws. Suitable for all common windows and doors made of plastic, wood or metal. ROBUST AND DURABLE-Our window vents are made of high-quality metal quality, not easy to rust, strong and durable, and have a long service life. EASY INSTALLATION-Window locks are easy to install. Each Window Opener comes with screws, you only need a simple screwdriver to screw it, easy to use, no need for a drill to drill. < /p> PROTECTION - Also suitable as a cat and child safety lock, safety lock system for turning and tilting and turning inward opening windows. Ventilate the room safely and bring in fresh air. APPLICATION-Our window vent is suitable for all types of sliding windows and casement windows, and can help fix windows. Note: The data are manual measurement, please allow a 1-3cm error, due to the differences between the light and the display, there will be a certain color difference, the specific received in kind prevail.