I bought it to repel flies on a food counter. It works locally, meaning it covers the area where its wings reach, whether it has ultrasonic or infrared, I can barely hear them. Its construction materials are very cheap. Out of the 6 pieces I ordered, 2 came brand new with one wing already cut out of the two. Besides that, they are very easily cut like paper, and I end up making makeshift repairs and sticking them together (after 2-3 uses, three more were cut). It operates on batteries (I have used rechargeable ones to avoid constantly buying new ones), but in order to insert them, you need to unscrew it with a small screwdriver, and even the slightest pressure breaks the latch, making the whole device useless afterwards. Overall, it's expensive for nothing, considering that it might work perfectly for a maximum of 2 or 3 uses.