No personal experience with that chain - but can tell you that manganese steel in one of the toughest materials in the world. The reason you don't see more of it is because the stuff is so @$&? hard to machine! Normally a plasma torch is used to cut it. The lock itself would be the 'weakest link' in that chain.
That is apparently the same type of chain used on the 'New York Chain' product. But a better lock ups the protection level to '9' in that product.
Last edited by Burton; 01-21-13 at 05:21 AM.