For those who have reviewed this lock and mentioned the difficult locking mechanism and given it a rating of one star... who dresses you each morning? Yes the lock isn't a simple 1/4 turn type, it does require a full turn and the key must be fully inserted before you turn - that's it, it really isn't that difficult.
I've been using this on my motorcycle in central London for around 5 years now, and never had a problem... it stays exposed to the rain and other elements all year round, and the most I've done to it is a quick squirt of WD40 once in a blue moon.
While this is a secure lock, don't be fooled to think that it will fight off all attacks... if a determined thief wants your bike, they'll have it.... but you can make it difficult for them with this Abus.