M G DURAVENT 4PVL-A12R 4" x 12" Adjustable Pell Vent Pipe 4-D x 12"l, adjustable pellet vent pipe, adds 3" to 10" of length to 4" rigid pellet pipe, twist lock construction, can be used in both vertical horizontal installations, 4-1/2" od, designed for stoves that burn wood pellets, double wall air insulated pipe, inner wall of 012" super ferritic stainless steel, outer wall 018" laser welded galvalume, patent pending venting for stoves inserts that use wood pellets, UL listed for 3" clearance to combustibles in USA Canada, required for venting pellet appliance above 4,000'. Features Manufactured in United states Easy to use Highly durable USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.