The Thermacell MR300 Mosquito Repeller is a heat-activated device that repels mosquitoes for up to 12 hours without the use of sprays. It creates a 15 x 15-foot zone of protection, making it ideal for outdoor activities such as camping and hiking. The device is olive green in color and is EPA registered with the number 71910-2. The repeller uses a repel/deter method to keep mosquitoes away and is manufactured in Thailand.