Enhanced security: The Defender 3-inch security door lock reinforces inward swinging doors to withstand up to 800 lbs of force. An inside locking mechanism provides superior protection against unauthorized entry and break-ins. Not suitable for doors that open outward. Child proof design: Engineered as a toddler door lock to prevent unsupervised door opening. Ideal for homes with toddlers or babies. Adults can unlock easily in emergencies while keeping children from accessing restricted areas. Sturdy construction: Made from high quality aluminum, this 3-inch Defender lock delivers durable, long-lasting protection for inward swinging doors. Suitable as a home security door lock, top door lock for kids safety, interior door safety lock for bedrooms or apartments, and an additional child lock. Easy installation: Includes 8 screws (4 long, 4 short) and an installation manual. Optional instructional videos available for quick setup. With a little practice, it becomes a reliable door safety lock, reinforcement, burglar deterrent, yet remains easy to open in an emergency. Enhanced home security door lock: Provides peace of mind for parents and caregivers by preventing children from opening doors to strangers. Adds an extra layer of door security against unauthorized entry, creating a safer environment for seniors, people with dementia, and anyone home alone.