Thermacell Mosquito Repellent Refill Value Pack. 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 value pack comes with 4 butane cartridges and 12 insect repellent mats for the Thermacell appliance and will provide up to 48 hours of protection. Thermacell appliances sold separately.