The Ionus Chain 8900 offers great mid-level security by itself or as an ideal second lock for urban riders requiring an additional security option to supplement their heavier u-locks. Easy to use, easy to transport. - 8mm square hardened steel chain links - Pinned fabric sleeve protects bike's frame and paint job - Chain, lock body and supporting elements all made of special temper hardened steel - Two keys supplied with lock - Anti-drill protection plate at keyhole - Industry leading corrosion resistance makes this lock incredibly durable.