TECHNOLOGY & DETAILS: TURN IT ON… MOSQUITOES GONE: Thermacell Patio Shield creates a 15-foot zone of protection against mosquitos. Ideal for patios, decks, pools, porches, camping, and more HEAT-ACTIVATED: No cords or batteries. Powered by a safe and compact 12-hour fuel cartridge (included), 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 (3 included) 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. Easy to refill 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: Extend your warranty to two years with registration (automatic 1-year warranty included). Developed and Tested at our New England based R&D center. We stand by our products with a 100% satisfaction guarantee