For the backyard and beyond, the Thermacell Perimeter System is easy to install, and the 3-pack provides 675 sq. ft (62,7 sq. m) of advanced mosquito defense. Scent-free and mess-free; 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 15 ft (4,5 m) to create your continuous defense area. Simply add additional systems to defend even larger areas.