ThermaCELL Mosquito Repellent appliance Repels mosquitoes, black flies & no-see-ums 225 sq ft of protection (15'x15') Up to 98% effective Each mat lasts up to 4 hrs Odor-free Cordless...no plugs, no batteries Powered by a butane cartridge (lasts up to 12 hrs) On/off switch Woodlands camo finish Quiet...won't spook your quarry! Tested by the U.S. Army Ideal for any outdoor sport! Not recommended for altitudes above 4,500 ft If you're tired of creams and sprays that you have to repeatedly apply to keep the bugs off, then ThermaCELL is what you need. Just load & go. You won't have to think twice about your bug protection.