Instruct: Classify a given review as either positive or negative.
Query: Unreliable if left for long period of time.

I had my mongoose bike locked with this U-lock and left it overnight (in Brooklyn projects area) only to find out the next morning that the lock was busted up in pieces and the bike was gone, they probably used a hammer or something. I'm giving this review 2 stars instead of 1 because i don't know exactly how much time it took for them to brake it. One things for sure i wouldn't trust this lock a specially if left on for long period of time. (Note: i used lock alone without the chain).