Providing a 15' x 15' "Bug-Free" zone, ThermaCELL is cordless, odor-free, and up to 98% effective! Great for backyards, camping, hunting, fishing, and more. ThermaCELL works by heating a mat saturated with mosquito repellent. As the mat is heated, the repellent is released into the surrounding area. ThermaCELL has also been shown to be effective against black flies, no-see-ums, and sand flies. The appliance is EPA approved, does not contain DEET, and has no open flames. Operates on a single butane cartridge (included). Original ThermaCELL Repellent comes with 3 mats to provide 12 hours of protection. Olive MR-GJ and Realtree APG camo MR-TJ models have a quiet on/off turn dial instead of switch. Weighs 0.7 lbs.