40" medium duty hardened chain is wrapped in soft nylon sheath, sewn all the way to the heads to prevent ripping or tearing. Each head is covered in a soft silicon to prevent dinging. 7mm diameter chain with a forty inch length lets you lock up the frame and either front or rear wheel. Wear this lock around your torso or toss it in your pack, either way, it's security is sure to keep your bike safe with a security rating at 7. The dimple key and cylinder design is simple and easy to use, three keys provided.