3 Stop metal home security door lock with 8 screws (4 long and 4 short) for flexible mounting options. Strength and protection - The door latch lock can withstand up to 800 lbs of force, about 12 times stronger than a standard deadbolt, providing effective protection against forced entry. - Front door lock helps you feel secure during the day or night, enabling more relaxed rest. - This lock is an ideal choice to enhance home security. Easy installation - Easy to install with a power screwdriver and drill in about 5 minutes on the door frame. - Comes with an installation manual for reference during setup. - To unlock, press the upper and lower grooves and pull horizontally to the fully unlocked state for quick release in any situation. Child and elder safety - Child protection function: spring-loaded design prevents young children from opening the door to strangers. - The flip lock adds protection when you are away, guarding against hazards such as streets or pools. - Provides additional security and peace of mind for the elderly or women living alone at home. Compatibility and use - Suitable for most inward-opening doors, including apartment doors, bedroom doors, front doors, back doors, patio doors, and courtyard doors. - Note: Not suitable for French double doors, garage doors, outward-opening doors, doors with gaps less than 0.07 inches, or doors with misaligned frames. Also suitable for both tenants and landlords seeking added security.