Waterproof cover design: the dust cap of the lock can prevent sand and rain from entering the lock cylinder, and prevents the lock cylinder from rusting. It has a high strength and rigidity, high temperature , wear-, cut resistance as well as improves violence resistance, significantly safety of your property 2 keys and waterproof lock head: We have provided two keys for the bicycle lock to prevent the key from being lost It is your perfect anti-theft device. The lock opening is equipped with a waterproof opening, so that the lock cylinder cannot be corroded in rain or snow.