Isokern manufacturers a chimney system which is impervious to wear and tear. Our Dual Module (DM54) Chimney System has been venting homes and buildings near the Polar Circle for decades. Over the last quarter century, Isokern Chimney Systems vented over 155 million meters of chimney in North America. Component-based with an inner liner and outer casing, they are the only all masonry chimney system tested and listed to UL103HT (High Temperature) standards. The dual modular design allows for more diverse, lightweight, masonry-type installations and each component is built with tongue and groove construction with offset joints, enabling a tighter fit for maximum safety and consistent installation. In addition, the DM Chimney System with 100% zero-clearance to combustibles, makes it the easiest flue system to install.