The U 10309 Swing Bar Lock is designed as a secondary lock for hinged swing-in doors, providing an additional layer of security while allowing safe visibility and ventilation by keeping the door slightly open. This door stop lock is especially suitable for environments such as offices, hotel rooms, and family homes, reinforcing door security from the inside. Crafted from durable synthetic material, it is built to withstand frequent use and ensures reliable performance as a manual door latch. Installation is straightforward with included fasteners that securely mount the lock to standard door frames, though it is not suitable for double or metal doors. This lock helps prevent unauthorized entry by securely latching doors inside, giving users peace of mind in various settings.