Excellent product, just what I needed to stop distracting myself with my cell phone. It is easy to program, you simply press the top left button once to turn on, then twice to increase one hour and once to increase 5 min, when you have set the time you want to lock it, you press the same button for 5 seconds and voila!
I recommend trying it first without the cell phone to see that everything is fine, but in general I am very satisfied with the product.