For the backyard and beyond, the Thermacell mosquito repellent perimeter system is easy to install and the 3-pack provides 6.7 m² (675 sq. ft.) of advanced mosquito protection. Scent-free, mess-free mosquito defense, the perimeter system is ideal to surround your backyard, patio, or pool with discreet mosquito defense. Simply plan out the perimeter around your entertaining area, insert a fresh cartridge and mat, and enjoy hours of distraction-free fun. Dual and flexible mounting options for landscape or deck applications using the included stakes or mounts. Place a repeller every 4.5 m (15 ft.) to create your continuous protection area. Simply add additional systems to protect even larger areas.