9" To 10" DuraVent DuraBlack Increaser 9DBK-X10 This increaser is used to increase from a smaller appliance flue outlet (9") to a larger diameter chimney or stove pipe (10"). Measures 7" long. 24-gauge strength Lock seams 18" clearance to combustibles Painted black Single-wall interior stove pipe for connecting wood stoves to manufactured chimney Economical and drip-free connection No need for cutting or crimping