Kryptonite's Evolution Series 4 1090 Integrated Chain is a 10mm-thick, six-sided link chain made of triple-heat-treated manganese steel for maximum strength. At 35.5-inches long, the Evolution gives you biking security in an easy-to-carry package. The links are covered with a weather-resistant nylon sleeve that protects your bike's finish, and it uses an integrated high-security cylinder that is pick, drill, and cut resistant. Three keys are included, including one that has a high-intensity LED bulb for convenient, easy unlocking in the dark. This chain has an anti-theft protection offer of $2,250, too.
Kryptonite's Key Safe Program is an easy way to ensure you always have access to your lock's capabilities. Simply register your key number with Kryptonite and if you lose your keys, your first set of replacement keys are free!