Our most popular thermacell mosquito repellent appliance, in a rich olive color, operates on a small butane cartridge which heats a repellent pad. The pad then emits a nearly odorless vapor to create a cell of protection, for up to 12 hours in an area approximately 15 feet in diameter! EPA Approved, consumer safe. For Refill purposes ALL Thermacell Mosquito Repellent Refills work in ALL Thermacell repellers, lanterns and torches.