Ideal to keep mosquitoes away, the lightweight Thermacell MR300 portable mosquito repellent device create a 4.5-meter (15-feet) zone of protection anywhere you want to be bug-free. Scent-free, DEET-free and compact, it can easily follow you from the backyard to the great outdoors. Turn it on to heat up and activate the repellent and within minutes you can enjoy your activities. This device provides up to 12 hours of protection and comes with a fuel cartridge and 3 repellent mats with a maximum of 4 hours repellency per mat and turn from blue to white once empty so you can know when it needs to be replaced.