ASPECTEK Ultrasonic Outdoor Animal Pest Repellent, Yard Sentinel RC Pest Repeller Pest Control includes Motion Detector, 4 Key Remote - Rodents, Cats, Rats, Mouse, Mice, Deer, Frequency: 15-18 kHz

This is a quality product! I purchased two explicitly for keeping the neighbor's awful dog from coming onto my property and harass me. Yes, the back covers are difficult to get back on, but they get easier with time after break in and learning the technique. The unit has many options and settings to make them versatile for various situations. Read the instructions carefully before you use this, for best results. Currently, I have both units side by side and one is set for the frequency for dogs while the other is on a rotating frequency to keep the dog from getting used to the sound Basically, it's keeping the dog from feeling comfortable in the area where it should not be. It's not foolproof, but it is absolutely helping 90 percent of the time and that is a win. The units seem well built, sturdy and weather resistant.

I thought I had already posted a review and I was just going to update it. Seems I didn't. So here is the scoop. In my case I guess it is impossible to prove it doesn't work. We just moved to this area and have a very nice 3 seater covered porch swing. Where we used to live there were squirrels, but they never cared about the swing cushion. Two days after setting it up in our new home a squirrel, or more, decided to chew a hole in the back of the cushion and pull out the fiber stuffing. My guess is to make a nest for the upcoming winter. Anyway, I put the cushion in the garage, ordered the Yard Sentinel and when it arrived I immediately set it up and positioned it facing the swing from about 15 ft. away. No squirrels came around. The audible tone would go off several times a day and was so disturbing that I turned it off. Still no squirrels. Then I thought I should put the cushion back on the swing to tempt the critters. Still no squirrels. Maybe they finished with their nest building. Maybe the device works. Whatever, there are no more squirrels and we are happy. Will let you know if anything changes. 9/22/14 Last week I noticed that the squirrel was back and seemingly immune to the Sentinel. I changed the position of the machine, the setting level, the motion control to continuous and placed it back outside. The next day I watched the squirrel climb up on the swing cushion and rip it open. I ran out and chased him away. I tried to modify the setting on the Sentinel, again, but this morning the squirrel just walked across the front of the machine and was unaffected by it. I decided to return the unit to Amazon but was informed that my "window" of opportunity had expired last week. I am now stuck with a device that does not perform as advertised. DO NOT WASTE YOUR MONEY!!!! This machine does not work, at least not for squirrels. I am very unhappy with Amazon.

Be patient in getting the settings right, and you WILL BE REWARDED! I planted grass in a place that has in the past always been dug up by some type of critter (voles? skunks? opposum? squirrels?). One year I replanted 3 times! With the Aspectek monitor, the grass - on FIRST planting - is 2-3 inches tall and thriving! It really does keep the critters away. The only drawback is the way-less-than-perfect cover that needs to come off in order to change settings. What a pain - it takes a whole lot of patience to put back on. Otherwise, this product would be PERFECT!

This device does function as advertised in the sense that it wasn't defective and it operated nearly continuously for three weeks straight until I stopped it, which surprised me. I used it in a sort of off-label manner however: I put it underneath my house set on continuous noise since there was already a raccoon living under there, and combined it with spraying coyote urine. I had hoped this would encourage the raccoon to find some other digs, but the high-pitched noise, bird-of-prey screeches, and strobe light merely turned my crawlspace into a critter discotheque. If a raccoon can live for three weeks with that constant noise, then I doubt it would actually repel one if used as suggested, as a yard deterrent. It should also be noted that I had some rodents enter the crawlspace during this period (and meet their doom as I control them via other means), so that's a double failure of this noisemaker.

Su función la hace, no tenemos ni un pájaro, pero eso de ultrasonido...¡solo sirve para los sordos! (con perdón para los sordos) ¡Que escándalo forma! Mi marido lo instaló sin avisar, y parecía que estaban torturando a un pájaro y a eso le sigue una alarma y luego una sirena... eso si, no hay un pájaro que tenga güevos de acercarse, las cosas como son, efectivo es...

Buen producto, sin problema para instalar, desde que lo coloqué no ha habido presencia de animales nocturnos.

Partially effective on some animals. Adaptor provided is of poor quality.

Useless

We live in a small community that is plagued by deer. Deer have learned that people will not tolerate the presence of predators (cougars/wolves) in our town, but will accept the risk of road collisions, destroyed gardens and attacks (yes, deer will attack and stomp anything they perceive as a threat, even someone pushing a baby stroller once). A cull is the answer to the lack of predators, but that is politically unacceptable. The misguided believe that the deer were here first and thus they are "natural"; from the perspective of a wildlife biologist I can tell you there is nothing natural about deer with no predation. Thus we have a very large deer population that is uncontrolled. We have planted "deer resistant" plants (they ate them) and even sprayed flowers with a garlic oil mixture (they ate those the next day). Our control was limited to me with a sling shot and this would usually result in a rotation; the one I hit today would not come back for a while, but some other deer would show up to take its place. We would be lucky to go more than two days without deer. I installed the device using the extension cord; ultra-sonic always on and sonic off set to the highest deer setting. PROS: It has been about two weeks since installing the Yard Sentinel and we have not had ONE deer since. CONS: Could be a bit more ruggedly constructed but I'm so pleased that it has worked so well (so far) I'm willing to give it five stars anyway. I will repost should the deer suddenly return and accept that their sudden absence was a coincidence.