The Thermacell Halo Mosquito Repeller effectively repels mosquitoes by creating a 15ft zone of protection. Our most advanced fuel-powered Repeller is contemporary in design and has several features that set it apart from other Thermacell devices. Ideal for use while entertaining, the contemporary design looks great on your patio, no spray and no mess, scent and DEET free; long-lasting 48hr fuel system with 4x fuel capacity can run on any number of 1 to 4 fuel cartridges. ZoneCheck provides a visual indication when zone of protection is created. Package contains- Halo repeller, 1 protective cover and 12 hours of refills - 3 repellent mats and 1 fuel cartridge. Requires 4 AA-batteries (not included) for ZoneCheck Monitor.