Giant's SureLock Tough 2 lock incorporates the strength of a heavy-duty chain with the simplicity and portability of a coiled cable lock. Hardened steel links surround a twisted steel cable for a lock that's easy to carry along for the ride but packs some serious protection. The cable is coated in a durable nylon cover that protects your bike's finish. The double bolt lock mechanism resists picks and drills so you can lock your bike up without worry.