Security: 4-digit combination lock with 10,000 combinations. Metal wheels are easy to control. The desired combination can be easily restored at any time. High security and strong anti-theft. High Quality: Double-layer construction, made of anti-rust zinc alloy, can resist hammering, burning and sawdust. Comes with a sliding weatherproof cover to protect the combination dial from further weather damage. Large storage space: the internal size of the combination key box is 90mm*70mm * 28mm (L*W*D), which can hold 5 house keys or 3 large keys at the same time, and also can hold car house keys, room cards and other items Easy to install: All necessary installation accessories (peephole installation and wall installation) are included. Bilingual instructions in Chinese and English are included to teach you easy step-by-step installation. Applicable places: garages, gardens, classrooms, factories, businesses, stores, universities, dormitories, homes holidays, etc. Easy access and safety.