Easy to use by being plugged into power outlets, no batteries will be needed, saving you a large amount of replacement. The electronic insect repellent is a plug and play device, as long as it works, the breathing indicator light will be one chamber, one unit is best! Ultrasonic mosquito repellent, electronic repellent, mouse repellent , rats, cockroaches, mosquitoes, flies, ants, spiders, insects very easy to use, just plug it in. Ideal for indoor use such as home, restaurants, hotels, hospitals, office buildings, warehouses, etc. 3-4 weeks - get the best result. 1 month later: completely eliminated depends on pest range Mosquito repellent is safe, non-toxic and non-irradiating. The ultrasonic frequency is inaudible to humans and pets, it is animal friendly, the ultrasonic repeller is guaranteed to be safe for your family and pets. For best results, one patch and one repeller are recommended because the ultrasonic wave cannot penetrate walls and solid objects. Adopt the latest