Reliable additional window security for inward-opening windows. Provide a high level of resistance against burglars. This additional security protects your windows and window doors made of aluminum, wood, or plastic. The security device is suitable for inward-opening windows and locks with a sturdy bolt lock. A key is only required when opening. All security-relevant parts of the device are made of hardened steel. The lock case is mounted on the window sash, and the strike plate is mounted on the frame.