Thermacell Mosquito Repellent, Patio Shield creates a 15-ft (4,5-m) zone of protection against mosquitoes. Use this sleek, colorful repeller on patios, decks, at the cottage, and more. No cords or batteries. Powered by a safe and compact fuel cartridge. Emits scent-free repellent that drives away mosquitoes. Powerful outdoor area repellent for people and pets. Includes one repeller, one 12-hour fuel cartridge, and three 4-hour repellent mats.