DuraVent M G 6DT-LB 6 Inch Dura Vent Duratech Locking Band Twist lock end rings: Allows the installer to safely and easily connect and disconnect chimney sections Without mechanical fasteners, encases insulation to prevent exposure to outside elements, no locking bands required For use with wood stoves, fireplaces, furnaces, boilers, ranges, water heaters, or other appliances fueled by wood, oil, coal, or gas, and zero-clearance fireplaces that are factory-built Clearances: 2 inch clearance to combustibles Use for extra security at pipe, elbow, and tee joints, optional Limited lifetime warranty: The best warranty in the industry, 15-year 100%, 15-year and up 50%, gives the installer and home owner the greatest peace of mind in a quality installation