10mm square link chain with a loud 90dB alarm - keeps your bike and other valuable items secure from attack and the alarm will scare off any would-be thief. Robust hardened steel construction with protective chain cover to protect your paintwork fro scratches. 4 keys included and replacement key service in the event that you lose your keys. Batteries included (2 x CR2032 batteries). Available in 3 chain sizes: 1.2m, 1.5m and 2m.