The Thermacell Mosquito Repellent appliance provides a 15 ft. x 15 ft. zone of protection against bugs. It effectively repels mosquitos, black flies, and other flying insects. It is silent and virtually odor free. This refill pack comes with one butane cartridge and 3 insect repellent mats for the Thermacell appliance and will provide up to 12 hours of protection. Thermacell appliances sold separately.