The ultra portable Thermacell Mosquito Repellent Unit MR300 gives you a 21 sq. meter barrier against biting insects. Powered buy a butane gas cartridge the unit uses a small internal flame to heat the inserted, scent free repellent pads to create a mozzie free zone of 21 square meters! The unit is ideal for outdoor entertaining, fishing, camping or anything else that requires mozzie protection, with a 12 hour butane cartridge and 3 x 4 hour repellent pads included you get 12 hours of mosquito free bliss. The MR300 unit is compatible with all refill repellent mats made by Thermacell, so to make the most of your time outdoors and protect yourself and family from annoying insects, this unit is a small portable option that does the job!