Description Thermacell Backpacker Mat Large 12 Pack Refill* (*please note that this product is a refill for use in the Thermacell Portable Mosquito Repellers and Lantern Mosquito Repellers) Mosquito, Midge and other Small Flying Insect Repellent Mats. When used in conjunction with the Thermacell range of Mosquito Repellers, each mat lasts a maximum of 4 hours. Each mat offers up to 4 hours protection Mat-only refill for use in the Thermacell Backpacker Mosquito Repeller (this refill does not include a butane gas refill but the mats are also compatible with other Thermacell Portable Mosquito Repellers) No spray and no mess. Scent-free and DEET-free The active ingredient is Allethrin, a synthetic version of a naturally occurring repellent found in chrysanthemum flowers
