The Kryptonite KryptoLok Bike Lock is the standard is U-Lock bike security. This U-Lock features a 12.7 mm hardened max-performance steel shackle with a hardened double deadbolt design for additional protection against twist attacks and cutting. The high security disc-style cylinder also adds protection against picks and drills plus a dust cover to protect the cylinder from the elements. Included are two keys with an ergonomic design to reduce the amount of torque and keeps them from bending or breaking.