Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Terrible...often stops by itself

First off I want to say that I do know how to use a mechanical timer-you have to turn the dial all the way to wind it up and then back up the timer to the amount of time you want it to timer for you, in order to have enough power in the spring to ring the alarm. The problem is that even if you do this, this timer will often get stuck or fail to ring entirely. It looks very nice, but unfortunately it completely fails to do what a timer has to. I would avoid this and all the other colors that this comes in, since you'll soon be purchasing another timer to replace it =(