SET YOUR OWN COMBINATION: The 4-digit combination lock takes 10 times longer to crack than a 3-digit lock. You can set your own combination from 10,000 unique options that you know are more reliable and secure. EASY TO USE: The unique side window design and large numbers make it easy to read. In addition, the ZHENGE combination lock features an advanced damping mechanism inside that allows each digit to click into place for greater accuracy and a better feel when entering the code.Setting or resetting the key is easy in just 6 steps by following the instructions on the back of the packaging. ROBUST CONSTRUCTION: This heavy-duty outdoor combination lock features high-strength zinc alloy bodies, hardened steel shackles, and expert craftsmanship. It is weather-resistant, cut-resistant, and saw-resistant, designed to be the most durable combination locks you can rely on. WIDE APPLICATION: This combination lock is perfect for indoor and outdoor use, including gym lockers, school staff lockers, canteens, pantries, toolboxes, door hasps, garages, sheds, fences, and general storage. NOTE: This is a large or medium-sized combination lock (1.73 x 0.86 x 3.11 inches, shackle diameter: 6mm), not really suitable for zipper holes.