The ThermaCELL Outdoor Insect-Repellent Lantern is the best option for keeping mosquitoes and other insects in any outdoor setting. Providing a 15-foot by15-foot mosquito-free zone, it is 98 percent effective (tested and used by the Department of Defense and the United States Army), making it the most effective insect repellent device on the market. It is also non-toxic, safe and non-intrusive, being DEET-free, silent, portable and odor free. It weighs only 13 ounces and can be used in any outdoor setting, including a nursery, rewholesale yard or retail garden center. Rather than a harmful toxin, ThermaCELL utilizes allethrin, an artificial version of a natural insecticide found in chrysanthemum flowers.