The kryptonite evolution 4 lock with bracket is a 13 mm hardened kryptonium steel shackle with patented deadbolt locking mechanism for extensive holding power a flat key high security with disc style cylinder and reinforced sleeve over crossbar and cylinder increases resistance against twisting leverage type attacks offset key location reinforced internal housing and overhead cam locking mechanism resists leverage attacks patented easy to use high security bent foot design and anti rattle bu