Whether you are deep in the woods, on your boat, or in the backyard, MR-450 Repeller effectively repels mosquitoes, black flies, and other biting insects by creating a 15 x 15-foot zone of protection for bug-free comfort. MR-450 Repeller is tough enough for any adventure. MR-450 features a zone of protection indicator that allows users to visually confirm the Repeller is up to temperature and establishing the mosquito zone of protection. Also includes one single pack refill.