The Kryptonite Evolution Mini 7 Dead Bolt Lock is made from a 13mm hardened max-performance steel shackle resists bolt cutters and leverage attacks. Patent-pending hardened double deadbolt design gives additional protection against twist attacks.  Kryptonite Evolution Mini 7 Dead Bolt Lock Features New double deadbolt design New sliding dustcover Higher security disc-style cylinder is pick and drill resistant Includes FlexFrame-U Bracket providing convenient multi-location u-lock transport 3 Stainless steel keys, including new key design and one LED replaceable key fob