Kryptonite Evolution Series 4 Disc U-Lock Key 46x53mm 1.8 x 2.1 Thickness in mm: 14mm Black14mm hardened Max Performance steel shackle resists cutting and leverage attacks Double deadbolt locking mechanism has extensive holding power High security, disc style cylinder with reinforced anti drill,anti pull protection system Sliding dust cover keeps the bunnies out 3 Keys one lighted with high intensity bulb and replacablebattery Key safe program 8 10 Security Rating TECH SPECS Internal Lock Size Imperial 1. 8 x 2. 1 Primary Color Black Lock