I have had my tattle tale for over a couple of years now. I had a problem with my dog getting on my bed during the day while I was away at work. If I was home she would hang out with me, I don't allow my dog to sit on my furniture. This thing worked from day one and I have recommended it to friends who now have multiple. We just bought a new sofa and want to keep the dog off of it, so I bought another one. This thing could be more sensitive, but it is sensitive enough for my dog, 65 lbs. It will go off if I toss a shirt down on my bed nearby, that seems sensitive enough to me. The sound is merely annoying, it isn't an alarm just a loud piercing beeeeep. If you have a medium to large size dog I suggest trying it out. One more suggestion use it on a "cushiony" surface for best results, a hard surface won't move as the dog does. So if you are trying to keep a cat off of a table this won't do much unless the cat goes near it. I don't think it actually senses motion, it needs to be lightly jostled to go off. A good product though.