? STRENGTHEN HOME SECURITY - High-grade Steel window locks security bar block criminals from entering through sliding glass windows or patio doors. Windows open in a fixed position for fresh air. Perfect for window air conditioner units or ventilation. ? ADJUSTABLE - The sliding door security bar extends from 15 1/2" to 29 1/2" with the 22 adjustable settings. Lock the height in place with the spring clip and the long screw help to reach the very small adjustment of the window's opening. ? STOP FORCED ENTRY OR UNEXPECTED ACCIDENT - The steel spring clip provides extra resistance from forced entry and ensures long-term use. Burglars can't reach it from the outside when correctly installed. Prevents children from falling out of open windows. ? NOTICE- BEFORE BUYING, MEASURE the window or door track where the guard will be placed . Window tracks MUST be at least 1 inch wide. The security device is 1 inch wide on every side. ? EASY TO INSTALL - Unique design. No tools required. Stick the lock bar on the window /door track with the supplied adhesive strips. It stays well and doesn't fall out when properly installed and adjusted. Removes easily in emergencies. Fits discretely in window / door tracks and looks decent.US Patent Pending. All Rights Reserved.