Shasta Vent All-Fuel HT Chimney is a double wall, solid-filled residential chimney featuring .020" type 304 Stainless Steel inner and outer walls with a 2" clearance to combustibles. All-Fuel HT Chimney also features precision engineered twist-lock end rings and quick and easy Locking Bands. The high-temperature ceramic blanket insulation is encased between the stainless steel walls of the pipe sections to maintain a strong draft, while maintaining a relatively cooler temperature on the exterior wall. In installations where offsets are required up to four 30 Degree elbows, each capable of rotating 360 Degrees, can be used in the system. The Shasta Vent All-Fuel HT Chimney is ETL Listed by Intertek to the HT requirements of UL 103. Tested to 1000 Degrees F continuously, 1400 Degrees F for 1-hour, and 3x 2100 Degrees F for 10-minutes as would be encountered in a creosote fire. Please Note: All Stove & Chimney Pipe is chosen and classified by the inside diameter. If your flue has a 6" Inside Diameter you will choose from the 6" Stove and Chimney Pipe categories.