16mm hardened MAX-Performance steel shackle Patented pending hardened double deadbolt design gives additional protection against twist attacks Highest security disc-style cylinder is pick and drill resistant Protective vinyl coating Sliding dustcover protects cylinder from the elements Includes Transit FlexFrame-U transportation system which allows for versatile carrying 3 stainless steel keys one lighted with high intensity LED bulb & replaceable battery Key Safe Program Rated 9/10 on Kryptonite's security scale Optional ATPO - £ 2,500 Product dimensions: 4” x 8" (10.2cm x 20.3cm) Product weight: 4.45 lbs (2.02 kgs) Sold Secure Bicycle Gold certified