ThermaCELL Fuel-ZoneGuard Multi-Insect Repellent Refills 2 Fuel Cartridges/6 Mats 24h. The first and only EPA-registered area repellent for black flies and no-see-ums these refills protect from mosquitoes black flies and no-see-ums (gnats). Not for the common house fly. Specifications for ThermaCELL Fuel-ZoneGuard Multi-Insect Repellent Refills: Manufacturer: ThermaCELL Age Group: Adults Application: Outdoor Insect Repellent: Yes Active Ingredient: Prallethrin Protection Time: 60 hrs 24 hrs Features of ThermaCELL Fuel-ZoneGuard Multi-Insect Repellent Refills EFFECTIVE ZONE TECHNOLOGY: Multi-Insect Repellent creates a 15-foot zone of protection against mosquitoes and a 10-foot zone of protection against black flies and no-see-ums. 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. Package Contents: ThermaCELL Fuel-ZoneGuard Multi-Insect Repellent Refills ThermaCELL MI2: Fuel-ZoneGuard Multi-Insect Repellent Refills 2 Fuel Cartridges/6 Mats 24h