DuraVent DuraTech Stainless Steel Exterior Trim for Wall Thimble - For 8" Inner Diameter: A venting pipe with an inner diameter of 8" is required for this unit. Note: The wall thimble seen in the main image is not included. Do you worry that your pipe system will deteriorate over time? Do you wish there was a way to prevent that from happening? Then you've arrived at the right location! This Exterior Trim Wall Thimble from DuraVent's DuraTech line of products will fit right over your 8" diameter piping providing a rigid fixed opening and an accurate mounting surface to minimize the possibility of distortion. With interior walls that are 25% thicker than the competition, you can rest assured that the sections designed to prevent distortion won't distort themselves. So, if you want a stress-free installation, make the switch now!

Size: 8 Inch Product Dimensions: 16" W x 16" D 2" clearance to combustibles No locking bands or mechanical fasteners required Exterior trim wall thimble NOT included Inner wall is 25% thicker than competitive chimneys for an extra margin of safety Designed for normal continuous operation at 1000 degree Fahrenheit flue gas temperatures For use with wood stoves fireplaces furnaces boilers ranges water heaters or other appliances fueled by wood oil coal or gas