Mindy is based on zinc alloy which is extremely durable. Ideal for medium to high risk of theft, the A&AF series Mindy padlocks are recommended for a wide range of security requirements. All models in this series have a paracentric keyway, zinc alloy plated cylinder cores and hardened steel shackle.Unique Lock core1.The key steps for 0.05mm;2.Leaf blade error 0.01mm;3.Locking plate and a locking groove clearance is 0.1mm;4.Spring leaves and the single type, as long as any side force can not be opened;5.Stainless steel lock, super anti violence on;6.The magic key to change and the error is 1, then automatic idle can not be opened.Hard to Duplicate The padlock comes with 3 keys which is important as the keys are too unique to duplicate easily. Hard to be Cut Off The lock is built to resists being picked by a shim (along the sides of the shackle), and also has a unique internal mechanism that is more difficult to pick. And, because there is a metal barrier that blocks the shackle, it is also more difficult to clip with bolt cutters. Good to Know Our company is committed to providing each customer best service. Wish you have good shopping experience in Unique-One store.Any issue please feel free to contact us.Thank you very much.