4vp-24, 4″ x 24″, pellet stove pipe, type l vent, tested & listed to ul-641 standard & ul-103 standard, proven coupling joint connects in seconds to assure joint integrity, gasketed joint design, double wall design with 1/4″ airspace, inner wall 304 stainless steel, outer wall paintable galvanized, rolled over male end eliminates sharp edges, 1″ clearance to combustibles.