A U-lock is the best and simplest bike security against theft. A strong steel bar is very difficult to cut in a short time, and a lock with a 5-digit code provides 100,000 combinations. Specifications: Material: durable steel + plastic Number of code digits: 5 Possible number of combinations: 100,000 External dimensions: 17x25cm Internal dimensions: 11.5x19cm Thickness: 15mm