Keep your Thermacell Appliance or Lantern loaded with skeeter-beating Mats! This Refill Value Pack comes with 4 Butane Cartridges and 12 Mats that work in every Appliance and Lantern that Thermacell makes. Each Mat provides up to 4 hours of repellency and each Cartridge lasts up to 12 hours offering you a total of 72 hours bug free! About Thermacell: All Thermacell Mosquito Repellers, Mosquito Repellent Lanterns, and Mosquito Repellent Torches work the same way and all are able to use any Thermacell repellent mats and refill cartridges. Thermacell repellent devices repel mosquitoes by creating a 15ft x 15ft zone of area repellent. This repellent, allethrin, is a synthetic copy of a natural repellent found in chrysanthemum plants. Thermacell repellent devices are powered by a butane cartridge. Butane provides the cordless, portable heat that activates the devices. The heat generated by the butane cartridge is directed to a metal grill. A small mat saturated with repellent is inserted on top of the metal grill. Heat disperses the repellent from the mat into the air, creating the zone of protection. The Thermacell Mosquito Repeller system effectively repels mosquitoes, black flies, and other biting insects by creating a 15 x 15-foot zone of protection for bug-free comfort. Ideal for use while you are camping, hunting, fishing, gardening, and around the backyard, Thermacell products have been evaluated by the EPA for safety and effectiveness. Repels mosquitoes, black flies and other biting insects Virtually odorless, perfect for hunting 4 Butane Cartridges and 12 Mats offer 48 hours of protection Compatible with all Thermacell Mosquito repellent Appliances and Lanterns Order today!