Strongly recommended where your chimney pipe exits the stove jack in your tent or shelter, the Winnerwell 2.1” Double Wall Pipe Section is compatible with small size Winnerwell wood stoves with 2.1” diameter pipes. The double wall design prevents the hot flue pipe from directly contacting your exit point. The exterior diameter is 4.7 inches and is designed to fit perfectly with Winnerwell Silicone Flashing Kit.