Keane & Jacy Linens White 100% Linen Hemstitch Dinner Napkins 20" X 20" (Set of 4) FUNCTION: It uses the principle of infrared detection, in the detection of small animals at the same time to issue ultrasonic waves to drive small animals. It can help you stay away from nasty stray dogs, stray cats and other small animals harassment, thus protecting your property and your garden. Because it is a portable design product that can be installed in your home, garden, or anywhere in the courtyard. REMINDING: This product can be used with low battery power, the product is only to drive the animal without any chemicals, it is only issued 25kHz ultrasound to drive them away. Will not have any harm to the human body.And will not hurt your own cats or dogs or other pets. SUGGESTION: The animal repeller is activated by motion and combine with ultras sonic sound, flashes light and sound to chase unwelcome small animal out of your place. If the animal just stay a place and no move, this device would be not activated and no apperant result. So please found out the route that cats, dogs, mice, rats, squirrels would be move or appear, then plug or install this device and will be works great on deterring them. INSTALL: Its very easy to use, you can put the stake into the ground at any place you want, or hook it in your fence, best choice for your yard , garden, fruit trees, farm or flower beds. CUSTOMER SUPPORT: We offer you 100% risk-free satisfaction guarantee to let you buy with confidence. Get 100% money back if the animal repeller doesnt satisfy your needs. Our animal repeller have 2-year WARRANTY!!!