Abus takes their security very serious, and the Granit 640 U-lock is no exception. Designed to be one of the most rugged and durable U-locks out there, the Granit lock features a 12mm hardened steel round shackle, Abus Plus cylinder for high tamper and lock picking protection, and a flat bolt ball locking mechanism for easy locking. Not only is it extremely strong and durable, but the Granit is crafted from a lightweight alloy in order to optimize weight. Includes 2 keys, one regular and one LED key.