Safer: The lock cylinder of the U-shaped lock is made by C grade pure copper blade, which has precise structure to prevent technical opening. In addition, this bicycle lock comes with 2 rustproof pure copper keys which have intricate serpentine slot, it will be more secure and you never have to worry when you lose one. STURDY AND DURABLE: The heavy-duty bicycle U-lock is made from a high performance hardened steel shackle that resists cuts and pry attacks, it will provide your bike with more security. The silicone cover makes it resistant to dust and dirt to extend the life of your lock, this U-shaped lock will protect your bike from scratches. PORTABLE AND SAVE SPACE: The mounting bracket on the bike can fix the U lock and take it with you at any time.High quality convenient mounting bracket means your lock goes with you, no additional packaging required. No more worrying about leaving the house without your lock. Design and Performance: The silica gel coated layer protects the U-lock bike lock to prevent scratches. Waterproof bicycle lock with mounting bracket, The mounting bracket bracket is easy to install, you can refer to our instructions to install it. This easy and convenient installation allows you to take and store your lock quickly when going out.