Kryptonite security levels: 1 (Low) - 10 (High) 16mm hardened Max-Performance steel shackle Patent-pending hardened double deadbolt design gives additional protection against twist and cut attacks Highest security disc style cylinder is pick and drill resistant Sliding dust cover to protect lock mechanism from dirt and debris 3 redesigned stainless steel keys - one with integrated LED key fob Includes Flexframe U bracket providing convenient multi-location u-lock transport