Our non-positional lock system on the DuraVent® BV gas vent is the best lock system on the market today. The incorporation of the DuraTab® feature simply improves our lock system by adding flexibility and meeting market needs. The BV line of DuraVent® round vent pipe and fittings is designed for use on approved gas appliances in residential and light commercial and industrial applications.

DuraVent® Increaser, 4 x 6 in, Aluminum, Finish: Galvanized, Additional Information: For Use With Type B Gas Vent System, DuraLock® and DuraTab® Locking Device

• Use to increase vent diameter