General description The 1Pack Security Door Lock is a heavy-duty steel window guard lock designed to enhance security for various entry points, including front doors and windows. It prevents forced entry while allowing the door to open slightly, providing a gap of approximately 30-50mm for identification of callers before fully releasing the door. Technical specifications Material: Heavy-duty steel Opening gap: Approximately 30-50mm Installation No drilling or chiseling required for installation Usage Provides reliable protection for hotels, doors, storage rooms, windows, etc. Cannot be unlocked from the outside after installation