Impact Ultrasonic Rodent Repeller Impact Ultrasonic Rodent Repeller has high-frequency dual speakers that will repel rodents from the area you want to protect. Unlike its premium counterpart the Rodent Free, the Impact Ultrasonic Repeller does not need to be directly plugged into the wall. Features High-frequency dual speakers to drive rodents away (inaudible to humans) Electronic device with adaptor Four different modes to choose from – Duo: Intermittent impulse attack waves plus frequency sweeping attack waves will be projected from both the dual speakers and transducer. The beat frequency produced during the DUO mode is normal operation Trans: Intermittent impulse attack waves will be projected from the transducer system Ultra: Frequency sweeping attack waves will be projected from the dual speaker system Test: The device will shift its output down into the audible range of human beings for a reassuring check of its ultrasonic output when switched to the Test mode. The shrill, shock, unregulated siren-like sound produced simulates the sound that pests hear continually. I generally didn’t have much faith in ultrasonic repellers, but I figured I would try this product because the seller would help if it didn’t work. I didn’t have power in the attic to plug the unit into, so I simply placed it on top of a bookshelf (about a foot from the ceiling) in the room where the noises were the worst. I can hear some clicks from the unit when I’m in that room, but otherwise, I don’t notice it. After a few days, the mousie noises cleared up! I’ve been keeping track, and the mousies try to return about once a month now. I don’t have to do anything special – the mousie noises never last more than a day or two and the unit drives them away. I just leave it plugged in all the time. I’ve had it for about 6 months now, and I’m very happy with my purchase. – Sam *It works wonderfully! After weeks and weeks of killing mice only to have another one take its place I got tired and started doing a little research. I found a lot of ultrasound mice repellents but all the others reviews were mixed. This one looked the most promising and I have to say that since I plugged it in I have not seen a single mouse in my apartment. I have no clue how they got in but I am extremely happy they are gone and will never return! The fabulous product would recommend to anyone having trouble with mice in their home. – Christopher Instructions for Use Just plug into electricity and the unit can be used indoors at any time. You will begin to notice a difference within the first two weeks however please note you may see increased activity first as the rodents will come out of hiding. Leave the unit plugged in day and night, all year round for continuous protection from rodents. Please do not place the unit on carpeted surfaces, behind furniture, draperies or other soft objects as they will absorb the sound waves. Do not place the unit next to your ear when operating the test mode. Do not use the unit outdoors or let the water come into contact with the unit.