Original Thermacell Mosquito Repellent Refills effectively repel mosquitoes by creating a scent-free 15 ft zone of protection when used in fuel-powered Thermacell Repellers. Ideal for use while you are camping, hunting, fishing, gardening and around the backyard.Features:Includes 300 hr of mosquito protection refillsFor use in fuel-powered Thermacell Repellers, Lanterns and TorchesEach repellent mat lasts up to 4 hr and each fuel cartridge lasts up to 12 hrNo spray and no mess, scent-free and DEET-freeActive ingredient is Allethrin, a synthetic version of a naturally occurring repellent found in chrysanthemum flowers