The frame-mounted additional lock is a universal supplementary lock designed for installation on window frames. Do you want to easily enhance the security of your aluminum, wood, or plastic windows? This universal additional lock makes it simple for you. The supplementary lock is mounted at the top of the window frame without drilling into the window sash. Once in use, the solid steel bolt consistently secures against intruders. The locking mechanism engages automatically and can be conveniently opened without a key.