Really good chain, secure and sturdy without being too cumbersome. Keys are unique to your chain, three keys supplied which is great. Fabric chain cover is secured at both ends so doesn't ride up and scratch bike. Good length to enable securing to rails etc. Very happy with this purchase, price was sensible too.
Each chain comes with a different set of keys. Tried to use a friends set of keys for the same chain and it did not work. Safe option. It would not be easy to cut it. The cover protects the chain from dust and rust. The only thing I did not like is the holder. Mine broke after a couple uses because I could not put it in an easy to reach place on my bike. Now I just took it of and put my chain around the seat. Overall very convenient.
I've been using this lock for a while, and it was good for a time, but after a about 6 months the mechanism started to stick. Then unfortunately my bike was stolen in broad daylight from a train station lock up whilst using this product.
I have only used this product for a week. First 5 days it was brilliant. Past two days it has been increasingly difficult to actually lock it and then he key broke off in the lock under minimal force ( I was jiggling the key because the it was refusing to lock and the key also would not come out). Poor performance, I was lucky I was at home because if this had happened whilst I was out I would have had to leave my bike unlocked.