The Krytonite Krytoflex series 2 mini D lock is a hardened kryptonium steel shackle with pantented deadbolt locking mechanism for moderate to high crime areas. The Krytoflex series 2 mini D lock is made from 13mm hardened krytonium steel with a patented deadbolt locking mechanism for extensive holding power, high security disc style cylinder & reinforced internal housing increases resistance to twisting & leverage type attacks. An offset key location & overhead cam locking mechanism resists leverage attacks.