Live life outdoors with Thermacell. Earning a consistent 4.7 stars or more in leading outdoor retailer reviews, Thermacell zone repellers create a zone of protection from pesky mosquitos, midges and other small flying insects, giving you the freedom to enjoy the outdoors. Thermacell repellent devices create a 20m² zone of protection. The repellent used, allethrin, is a synthetic copy of a natural repellent found in chrysanthemum plants, meaning no nasty smells, harmful sprays or oily lotions. 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, with a small mat saturated with repellent is inserted on top of the grill. Heat disperses the repellent from the mat into the air, creating the zone of protection. 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.