Just click it on, and the new Halo Mosquito Repeller provides odorless, invisible, continuous protection from mosquitoes, including those that can carry Zika, West Nile, and other illnesses. Contemporary in design, the Halo features a new long-lasting 48-hour fuel system, as well as a ZoneCheck system that provides a visual indication that the Halo is creating a Mosquito Protection Zone. The Halo is incredibly effective and easy to operate. Includes MR-D201 and one single pack refill.