Unlike traditional pest control, the Ultimate AT is safe to use around your family and pets. It does not use any chemicals, traps, or sprays, and it is silent to humans. Although you may see other electronic pest repellers at large chain stores or home improvement stores, they are no match to the Ultimate AT! Many of the store-bought units are made with paper speakers, so they may only last a few months before they quit working. The Ultimate AT emits sound from a ceramic high-pressure transducer – a very powerful, high quality ceramic speaker. Some types of electronic pest repellers claim to work inside your walls, but this feature alone won't repel anything already living in the rooms of your home. For example, a repeller that only works inside your walls will not target the roaches already living on your counter tops or floors! The Ultimate AT utilizes Electro-Vibrawave technology throughout the wiring in your walls, and fills the inside rooms of your home with a piercing high-pitched ultrasound that only the pests can hear. These technologies combined with powerful negative ions make the Ultimate AT the best indoor electronic pest repeller you can buy!