Thermacell Mosquito Repellent Refills - 48 Hours - Original Refills keep your Patio Shields, Lanterns, Torches, and other fuel-powered Thermacell Repellers fueled for the long haul, no batteries or cords needed. Always be prepared by keeping extra cartridges and mats in your tent, backpack, garage, or tackle box ready when you need it. Features For use in fuel-powered Thermacell Repellers, Lanterns, and Torches Each repellent mat lasts up to 4 hours and each fuel cartridge lasts up to 12 hours The synthetic allethrin formula is inspired by repellent extracts found in plants. Independently tested and EPA-reviewed for safety & effectiveness. People and pet friendly. Backed by the Thermacell Satisfaction Guarantee. See packaging for details.