No idea why it's so cheap, most stores are $120+ but if you're looking for the best portable bicycle chain lock then this is for you.
12mm six-sided, chain links made of 3t hardened manganese steel for maximum strength
Cinch loop for effective lock-ups using less chain
Offers nearly the same “in-use” length as a traditional 3.5’ chain, which means less bulk to carry
Durable, protective nylon cover with hook-n-loop fasteners to hold in place
Includes Evolution series 4 Disc Lock with 14mm MAX-Performance steel shackle
Higher security disc-style cylinder with reinforced anti-drill, anti-pull protection system
Patented*, oval hardened steel crossbar for extra security
Hardened double deadbolt locking for extensive holding power
Sliding dustcover protects and extends cylinder life
3 keys – one lighted with high intensity bulb & replaceable battery
Key Safe Program
Review
http://thebestbikelock.com/best-chain-lock/kryptonite-new-yo…
Amazon
http://www.amazon.com/Kryptonite-Bicycle-Evolution-Series-2-…
it's worth more than my bike :)