This is the Giant SureLock Flex Combo Coil 15 Cable Lock. This key-less cable lock is self-coiling and flexible for easy storage on your bike frame or back pack and provides 10,000 possible combo variations. Features: 10mm-15mm (0.39"-0.59") heavy-duty, extra-flexible, self-coiling cable with integrated resettable combination lock Zinc caps offer more protection against hitting attacks Tough vinyl cover protects against scratches 4 fluorescent digits; set your own combination from 10,000 possible variations - no keys to lose or forget Includes easy-to-use quick release bracket Note on Bike Locks: Bike locks provide deterrent to bike theft, however no lock is theft proof. Please research the area you plan to lock your bike, amount of time and time of day, and then which lock best suits your specific needs. Remember that locks may seem expensive, but a new bike is always more.