It definitely works. To save you time I have provided more specific information in the paragraphs below, which I entitled Scenario, Distance, Motion Detection, Radius, Ultrasonic, Flashing Strobe Lights, Customer Service, and Rating. Scenario: There's a small city-owned trash dumpster near my home and people like to feed stray cats there. The cats use my yard as their bedroom, bathroom, and playground. It wasn't unusual to find 5-8 cats in my yard throughout the day/night. The house is surrounded by a combination concrete and wrought iron fence, which is 5 feet high with the first 18 inches being concrete and the remaining height consisting of wrought iron, which the cats can walk through or jump over -- the fence is no deterrent. Distance: Using a tape measure, I determined the maximum detection distance is about 30 feet. Motion Detection: At the maximum setting, the motion detector activates at about 30 feet, but it won't activate if a barrier, such as a fence, glass, wall, etc., is between the device and the entity initiating the motion. Radius: The detection level from right to left is approximately 130 degrees and it's conical. If the motion is behind the device or to the side it won't work, it must be within about 130 degrees and even within the detection range, it won't detect motion if there's a barrier such as a fence, wall, glass, etc, between the device and the entity initiating the motion. Ultrasonic: It's not ultrasonic but it's not loud either. I can't hear it at a distance of 30 feet, but at about 15 feet I can hear it. It's a very low clicking-type sound, which is activated when something enters the range of the motion detector. It's not annoying and it confirms that it's working. Flashing strobe Lights: The lights lags behind the motion detector activation. When the motion detector activates, first the motion detector turns a blue color and within about a second or two, I can hear the "ultrasonic" clicking sound. A couple of seconds later the strobe lights flash . Customer Service from the Seller (Four Corners Dist.) and the Developer (Hoont): Prior to receiving the device I asked Four Corners Dist, via an email through the Amazon.com website several questions regarding the distance/radius/strobe light, and I got a response within 24 hours, but the answers were generic and essentially echoed that on the Amazon.com website. I then contacted the developer (Hoot) by visiting their website and using their online email to ask similar questions to the ones I asked the seller. Hoont didn't respond. Rating: It worked right out of the box, without the batteries being charged. I'm an American residing overseas and I received the device via Amazon Global in 10 days, at no additional postage charge. It's been a week and instead of seeing multiple cats in the yard throughout the day, I saw one cat on the 2nd day, and one on the 3rd day, but they didn't hang around. I haven't seen any cats in the yard since then, but I do see them (in fewer numbers) outside the fence. As previously noted the motion detector can't penetrate the concrete fence and it isn't pointed toward the fence, but it still seems to somehow be deterring, but not completely scaring off cats in that area. I am considering buying a couple more and focusing them on the dumpster outside the fence, but the problem is that the device doesn't have a hook to hang it from a fence or tree; it comes with a stake which is placed in the ground. That's a problem because the solar panel needs to face the sun, so without a hook it can't be attached to a tree or fence. If the developer provided better customer service, instructions, and more insight regarding the radius/distance/etc, and if it came with a hook as well as a stake, l would have given it 5 stars. Update: heavy rain caused 2 of these devices to malfunction, they are now useless, so I am changing the ratung from 4 to 3 stars because drvices on the garden/yard should be weather proof.