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