Kryptolok series 2 ls u lock with bracket standard kryptolok with 13 mm kryptonium steel shackle and case hardened for security longer lock can lock front wheel and frame up safely extra long shackle u lock tough bicycle security for low to moderate crime 13 mm hardened high grade carbon alloy steel shackle resists hand tools flat key high security disc style cylinder patented easy to use high security bent foot design offset key location and overhead cam locking mechanism resists lever