For the backyard and beyond, Thermacell Patio Shield is easy to use and provides hours of scent-free, mess-free defense against mosquitoes. With no batteries or cords needed, the Patio Shield is convenient, portable mosquito protection, ideal for entertaining, gardening, at the cottage, and more. Features a 15-ft (4,5-m) zone of mosquito protection. Powered by a safe and compact 12-hour fuel cartridge.