The Kryptonite TKO Mini U-Lock features a 12mm hardened steel shackle with a bent foot anti-rotation design that resists bolt cutters and twisting leverage attacks. The lock disc-style cylinder side keyway is protected by a sliding dust cover and is pick and drill resistant. It includes two stainless steel keys with an ergonomic design to reduce torque and prevent bending or breaking. Rated at a 4/10 on our security scale, this U-Lock is good for quick stops in a metropolitan area, a couple of hours in the suburbs or all day & overnight in rural areas. This lock is also bundled with a KryptoFlex (4' 8mm) double looped braided steel cable for securing front wheel or accessories. These great features, coupled with our support programs like Key Safe, Anti-Theft Protection, and a Lifetime, make Kryptonite Bicycle Locks the best choice for protecting what you value.