DVL Collection 5"-6" Double Wall Stovepipe Increaser The DVL 5"-6" Double Wall Stovepipe Increaser is a component that is used in a typical venting installation. Use to increase from a smaller appliance flue outlet to larger diameter chimney or stove pipe. Features: Inner Diameter: 5"-6" Use to Increase from a Smaller Appliance Flue Outlet to a Larger Stovetop Diameter Height: 7" UL Listed DVL double-wall stovepipe completes the venting system when used with one of DuraVent chimney products, such as DuraTech or DuraPlus. DVL double-wall, the air-insulated design reduces clearances to combustibles from 18" to 6" the closest clearance to a wall of any connector pipe. DVL improves stove performance by maintaining high flue gas temperatures for a strong, steady draft. Because the inner wall is stainless steel the flue heats up faster, stays hot longer, minimizes the formation of creosote, and has the same life expectancy as the chimney. Adjustable lengths eliminate the need for cutting or crimping. Required for Manufactured Home installations. See the appliance manufacturer's installation instructions.