御漢坊

What are the merits of Ultrasonic Pest Repellent for driving away rats and cockroaches?

　　Currently, there are many brands available in the market. How do we judge the merits of Ultrasound apart from hearing from a friend who has used it? There is a simple way to judge it. Generally, these products have a test button because we cannot hear ultrasound. The test button is to lower the frequency of ultrasound so that we can hear it. When you press this button, it will produce harsh sounds. If the sound is loud and harsh, it means the performance of the product is good. But if the volume is not very harsh, it may not be very easy for the product to get rid of rats and cockroaches.