ThermaCELL MR300 is a portable mosquito repellent device that creates a 15-foot zone of protection from mosquitoes. It is ideal for use in backyards, on patios, while camping, fishing, or hunting. The repellent is DEET-free and odorless, making it safe for use around children and pets. The device is easy to use, simply insert a repellent mat and a butane cartridge, and turn it on. One repellent mat lasts up to 4 hours, and one butane cartridge lasts up to 12 hours. ThermaCELL MR300 is a great way to enjoy the outdoors without being bothered by mosquitoes.