The Thermacell MR450 Armored Portable Mosquito Repeller effectively repells mosquitoes by creating a 15-foot zone of protection. This small rugged device can be taken virtually anywhere outdoors to repel pesky mosquitoes, stopping them before they can bite or bother you. It has a conveniently cordless, lightweight, minimalist design for use anywhere and it is extremely portable. It is ideal for use while camping, hunting, fishing, gardening, and around the backyard. It features ZoneCheck, a built-in LED that illuminates when the Repeller is up to temperature and emitting the Zone of Protection. The LED turns off when the temperature falls below the optimal level. It comes with overmolded rubber grips that provide sure handling no matter the weather. It’s rubber contact points on the back ensure a quiet placement. To use, simply insert a repellent mat and a fuel cartridge, then turn it on. The fuel creates heat. A view window lets you check for an orange glow to ensure the heat is on. Heat activates the repellent in the mat. After 15 minutes, a mosquito protection zone is formed. The repellent mat turns white after about 4 hours indicating it’s time for the mat to be replaced.