Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Don't expect the device to last too long

I have been through a couple of these devices now. When brand new, they seem to do the job, but after a few months they just seem to give up. Even with a fresh battery, it seems like the motion sensor stops functioning. And I live in a very mild climate with little rain, so I can't blame the weather. In general, the CatStop feels light and flimsy for the price, rather than a solid piece of engineering. So if you decide to use this approach to keep cats off your lawn, budget on replacing at least twice a year - plus a string of replacement 9v batteries.