2021 UPGRADED SMART CHIP: The ultrasonic pest repeller keeps on emitting more powerful and non-repetitive ultrasound between 22-65 KHz to attack the auditory and nervous systems of pests, which makes the pests never become immune to the sound. Work well on mouse, cockroach, spider, bedbug, mosquitoes, insect, rat, rodent, flies, ant, fleas and more pests.NO CHEMICALS, POISONS OR TRAPS: Ultrasonic mouse repellers work by producing tones which are inaudible to the human ear, but unbearable to mice and rats. You no longer have to worry about a child putting their hand in a trap or touching any poison. Ultrasonic mouse repellers won’t hurt you, your dog, cat, or most other household pets.EASY AND CONVENIENT TO USE: Simply plug the mice repellent into the electrical outlet, then the electronic pest repellent will start to drive pests out for good. Please install the pest repeller near the areas where the rat or pests might visit. 10-30 inches above from the ground is recommended for crawling pest, while higher for flying pest.LARGE COVERAGE AREA &LONG LIFE : pest reject is effective for an area up to 800~1200 Square Feet. Though the pest repeller works very well, but we recommend placing those sonic repellent in every room! Further, one rodent repellent can last for a couple of years, saving you hundreds of dollars in paying for exterminating pest control service.KEEP HUMANS & PESTS SAFE: The ultrasonic pest repellent is only audible to pests such as mice. Humans and pets won’t hear anything, and no harm to pregnant women and children. But if you keep hamster as a pet in your home, please do not use. VR MART Ultrasonic Pest Repellent Machine to Repel Lizard, Rats, Cockroach, Mos