JADUFHU Door Security Chain Lock, Heavy Duty Anti-Theft Black Metal Latch with Spring Anti-Pry Design, 4 Mounting Screws Included for Home Apartment Hotel Indoor & Entry Safety

【Reinforced Metal Structure】Crafted from thickened high-strength metal with premium black finished surface, this door security chain adopts an integrated molding process for overall sturdiness. It features excellent hardness, outstanding rust and corrosion resistance, and great deformation resistance. Not easy to bend or break under external force, it delivers long-lasting stable protection against prying and forced entry for your doors. 【One-Way Spring Lock】Designed with a sensitive spring press-lock mechanism that only allows indoor unlocking. It completely blocks external prying and unauthorized access, effectively eliminating home security risks. The door can be partially opened for air circulation while staying securely locked, ensuring safety at all times. 【Family Safety Protection】Serving as a reliable auxiliary safety device, this door chain adds an extra protective layer to your original door lock. It allows safe visitor identification and parcel delivery without fully opening the door, protecting indoor privacy. It also effectively prevents kids and pets from rushing out accidentally, avoiding unexpected safety hazards. 【Fast DIY Installation】Equipped with 4 matched high-quality mounting screws, no extra accessories are required. Precisely reserved mounting holes and optimized structure fit most wooden and metal doors perfectly. Users can finish installation in minutes without professional tools or technical skills. 【Universal Black Design】Featuring a sleek matte black minimalist appearance, the lock boasts a low-key and exquisite look that blends well with various home decoration styles. It is widely applicable for residential houses, apartments, hotels, guesthouses, offices and more, ideal for indoor doors and main entry door safety upgrades.