Metal-Fab 4" x 12" Adjustable Length Type B Double Wall Round Gas Vent Pipe UL Listed with SureLock Technology -4M12A-

Metal-Fab's round and oval Type-B vent is listed by Underwriters Laboratories for use with approved category 1 gas furnaces, heaters, and boilers. A category 1 appliance operates with a non-positive vent static pressure. The double wall design of B-vent enables the product to be used in homes and commercial buildings at close clearance to combustibles. Metal-Fab's B-vent design incorporates features that make installation quick, easy, and safe. Some of those features are: Elimination of sharp edges by hemming the flue and casing; Assembly & disassembly, without tools, using positive twist lock; -- UL listed to mate with other specifically identified and listed round gas vent, 3" thru 6" diameters, allowing you to add a new run of Metal-Fab B-vent to an existing run of common vent. Metal-Fab 3"-6" diameter B-vent pipe is now standard with new Surelock B-Vent Locking System. The patented locking system provides a secure lock with just the push of a tab, and can be easily disassembled by pulling the tab back out.