Description: Heavy-duty 3.9mm thick security steel chain links with ultimate strength - cut-resistance, anti-theft Durable protective nylon sleeve protects the chain from rusting and scratching your bike frame Strong joint locking mechanism prevents the lock from being picked, keeping your bike safe and secure Comes with 3 keys for emergency Multifunctional for locking bikes, bicycles, skateboards, lawnmowers, ladders, gates fences, chair, trailers, doors or tool boxes sport equipment and etc. Specification: Color: Black Material: Steel and nylon sleeve Thick of Chain: 3.9mm Length: 80cm/ 31.5 inch 110cm/43.3 inch Package Includes: 1 Piece Bike Chain Lock with 3 Keys Note: Please allow slightly difference due to manual measurement. Color may be slightly different since different monitor. Thanks!