The Thermacell MR300 Portable Mosquito Repeller effectively repels mosquitoes by creating a 15-foot protection zone. The MR300 Repeller can be taken virtually anywhere outdoors to repel pesky mosquitoes, stopping them before they can bite or bother you. It has a great all-around use and is ideal for use while camping, hunting, fishing, gardening, and around the backyard. It has a conveniently cordless, lightweight, minimalist design for use anywhere and is extremely portable. The MR300 Portable Repeller has an ergonomic design which is comfortable, functional, and easy 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.