DuraVent 46DVA-16AB 4" x 6-5/8" Inner Diameter - DirectVent Pro Direct Vent Pipe - Double Wall - 16" Pipe ExtensionCategory: Vent Pipe AdaptorDirectVent Pro Collection 4" x 6-5/8" Inner Diameter Galvanized 16" Pipe Extension BlackThe DirectVent Pro 4" x 6-5/8" Inner Diameter Galvanized 16" Pipe Extension Black is a component that is used in a typical venting installation. The DuraVent pipe extension is used to add length to a straight length of DirectVent Pro. 8 ½” pipe adds 3”- 7” of length, 16” pipe adds 3”- 14 ½” of length, when used with rigid sections of pipe. Direct vent lengths feature a fully unitized, twist-lock construction. Use of sealant is optional, unless specified by the appliance manufacturer. Available in black or galvalume exterior (both feature laser-welded outer wall seams). Does not fit DirectVent GS pipe.Features:Length: 16"Use to Add Length to a Straight Length of DirectVent ProAdds 3" - 14-1/2"of Length to a Straight Length of DirectVent Pro PipeFeatures Laser-Welded Outer Wall SeamsDoes Not Fit DirectVent GS PipeDirectVent Pro features tight inner connections for superb performance, with no gaskets or sealants required (unless specified by the appliance manufacturer). All black pipe lengths, pipe extensions, and elbows feature laser-welded outer wall seams for a sleek finish. Low-profile locks and no hems or beads allow for a beautiful product that looks elegant in any interior. DirectVent Pro is a unitized, coaxial venting system designed for use with direct vent gas or propane stoves, heaters, and fireplaces.Looking for Simpson Dura-Vent? You found it! Simpson Dura-Vent has changed their name to DuraVent. DuraVent is a recognized technological leader in the venting industry. Consistently the first to market with new innovations in venting systems, DuraVent has captured a leadership position in emerging markets. DuraVent has patents for several products and continues to design safe and technologically advanced venting.The company's research into solving problems with corrosion, when biofuels such as corn are used, led to the break-through patent for PelletVent Pro. Scientifically proven materials and unequalled engineering make DuraVent products not only the best choice, or safest choice, but the only choice for professional quality venting products.