The Thermacell MR300 Repeller in Mossy Oak Blue Marlin scent is a scent-free outdoor mosquito repellent that provides 12 hours of coverage. This refill comes in a blue color and is designed for outdoor use. The repellent method is based on repelling/deterrent control, with no DEET or spray involved. Made of durable plastic, this model is ideal for camping, hiking, and other outdoor activities to keep mosquitoes at bay.