The Thermacell Large Mosquito Repellent Mat Refill Pack contains twelve mosquito and midge repellent mats. Each mat lasts a maximum of 4 hours. This refill pack can top up your supply of repellent mats. The mats are compatible with all Thermacell Portable Mosquito Repellers and all Lantern Mosquito Repellers. Also, the ideal refill pack for the Thermacell Backpacker Mosquito & Midge Repeller!

Features:

• 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