This is the small size (Mini) WEDGIT security bar for single hung or sliding windows or as a sliding glass door lock if you are using a pet door panel. It extends from 15” to 25.” I also have a large size (Maxi) to use as a sliding glass door lock without a pet door panel. Please check my other listing for more information. This lock twists the door or window into the frame for a more secure, efficient weather tight seal. This is not only great for added security but it also helps childproof your sliding glass doors and windows. Requires absolutely no tools Super easy & quick installation Swings down out of the way when not in use Much more secure and convenient than a broomstick at the base of your slider.