EFFECTIVE 15FT ZONE TECHNOLOGY: Fuel-Powered Refills create a 15-foot zone of protection against mosquitoes. This cartridge is compatible with fuel-powered Thermacell Repellers, Lanterns, and Torches. LONG-LASTING DEFENSE: Each repellent mat lasts up to 4 hours and each fuel cartridge lasts up to 12 hours PROPRIETARY FORMULA: Independently tested and EPA reviewed for safety & effectiveness. Repels tough mosquitoes, including those that may transmit Encephalitis, West Nile Virus, and Zika Virus. REPEL MOSQUITOES IN AIR, NOT ON YOUR SKIN: Repel mosquitoes without DEET sprays or lotions on your skin. Scent-free, no smoke, no flames. People and pet friendly. *For Outdoor Use Only Features: Includes: Two 12-hour fuel cartridges, and six 4-hour repellent mats Active Ingredient: 21.97% D Cis Allethrin Refill / Cartridge Type: Mat and Fuel Refills Weight: (6) Mosquito Repellent Mats 0.5 ounce (2) Butane Fuel Cartridge 2.0 ounces Model Number: R2