The Thermacell Portable Mosquito Repeller is the best portable defense against mosquitoes, providing an invisible 4.5 meter zone of protection. The Thermacell Mosquito Repeller comes with a fuel cartridge and 3 repellent mats that produce 12 hours of freedom from the worry of mosquito bites. It uses an interior-heating element to activate mosquito repellent contained in the blue repellent mats to create a zone of protection that stops mosquitoes before they come close to your skin. Scent-free and with no sticky sprays, the repeller creates an ideal mosquito-free environment the whole family can enjoy from the backyard to the great outdoors.