The key on this product has a thin area right above the notches that fit the tumblers. In my case, this caused it to break off in the lock earlier today (I did not apply excessive force, knowing from experience the hassles a broken key can cause ). Now, the only way of getting my bike off that stand is for me to go home, bring back my rotary tool and cutting disc and have at it (if that works, this thing is hardened steel) . The lock itself might be as safe as the Bank of England, but I would advise against buying this product because of the key.Update: the "13mm hardened steel shackle" on this lock took about five minutes to cut through with my little-bitty cordless Dremel, so I shudder to think how easy a job it would be for any thief with a "professional" tool. In retrospect, I am happy the key broke off and that I had to get rid of this lock.