The bike locks come in 3 different strength, heavy(10 lbs), Medium(5 lbs), and Small(3 lbs). The bike locks are all 3 feet and made from galvanized steal. It can withstands over 6 tons of pull force and 11 tons of cutting force. The chain is wrapped with 2 layered, the outer layer which is Rugged ballistic nylon sleeve that protects against scratches, and the inner layer which is 3/16″ padding that gives comfort when carrying on shoulder. The lock is a Shackle Magnum 3″ Discus Lock created by Master Lock, created with a Key retaining safeguard insures padlock is not left unlocked. The Patented Octagonal “Boron – Carbide” shackle is 50% harder than hardened steel, making your bike the safest on the street.