❤ Robust construction: Heavy-duty combination lock with high-strength zinc alloy body, hardened steel shackles and excellent hull technology. They are weatherproof, rustproof and anti-saw. They are designed to give you the most durable dial combination lock. ❤ Four-digit security. Our luggage locks use four digits, making it harder for thieves to crack your password. You can also remember four digits because you can set the combination to a pin or year of birth. ❤ Designed for security and ease of use. The ultra-durable zinc alloy body and hardened steel shackle ensure that your luggage lock can be completed through harsh airport handling. The black dial numbers and high-contrast white on the combination window make it easy to read combinations.