This is the premier chimney cap for solving common, wind-related draft problems. Wind problems often occur for homes that have hills, mountains, tall trees or taller buildings in the vicinity. This cap also functions as a conventional chimney cap by protecting the chimney from rain, snow, debris, and animals. It is made of Austenitic Stainless Steel T304 and is designed to fit round chimney liner and Class A solid pack chimneys. This Model works with the following types of chimneys: Single Wall Chimney Liner, Solid Pack Class A Chimney, B Vent, and Round Terra Cotta Flues. What's Included 3" Inner Diameter Copper Chimney Cap Features For round chimney flue Protect your chimney from the elements Designed to work with Class A chimney components Specifically designed to combat wind related drafting issues Specifications Item Number VSC-03 Model VSC Lid Size 13" Inner Diameter 3" Color Copper Warranty Limited Lifetime Warranty Documents & Files Chimney Troubleshooting Guide Warranty Guide Videos