Thermacell backpacker mat-only refills effectively repel mosquitoes by creating a 15 ft zone of protection when used with the thermacell backpacker mosquito repeller.No spray and no mess.Scent-free and deet-free.This refill does not include fuel cartridges.Active ingredient is allethrin, a synthetic version of a naturally occurring repellent found in chrysanthemum flowers.Includes 48 hours of mosquito protection refills, package contains- 12 repellent mats lasting 4 hours each.Type: Refill MatSpecies: Mosquito, TickQuantity: 12 MatsEffective Time: Up to 48 hrsScent Type: RepellentEffective Distance: 15 ftWick Capacity: 4 hrs per MatContains: Allethrin