DETAILS: TURN IT ON... MOSQUITOES GONE: Thermacell creates a 15-foot zone of protection against mosquitoes. This 12-hour refill pack containing 1 fuel cartridge and 3 mosquito repellent mats is compatible with all fuel-powered Thermacell Repellers HEAT-ACTIVATED: No cords or batteries. Powered by a safe compact fuel cartridge that lasts 12 hours, repel without smoke, flames, or citronella. Not a messy trap or gimmicky sonic. Independently tested. EPA reviewed for safety & effectiveness LONG-LASTING DEFENSE: Unscented repellent mats last up to 4 hours each and change color when time to refill. No mess, no DEET, no spray, and no on-skin chemicals make Thermacell a better solution NATURE-INSPIRED REPELLENT: Our active ingredient is based on naturally occurring repellents found in plants. We've harnessed its power to fight the toughest mosquitoes on earth (including in your backyard) THERMACELL GUARANTEE: All Thermacell Mosquito Repellent products come with a 100% satisfaction guarantee. Developed and Tested at our New England based R&D center. We stand by our products