DuraVent FasNSeal 14" x 18" 29-4C Stainless Steel Adjustable Vent Length front-glass This high elevation kit is

This high elevation kit is specifically for use with your Williams Natural Gas 20

104431 4RV-WB 4-Inch 105431 5RV-WB 5-Inch

both with black fireboxes to create a true statement fire

in three models including a Modern unit for a more contemporary feel

DuraVent FasNSeal 14" x 18" 29-4C Stainless Steel Adjustable Vent Length front-glass This high elevation kit isAll FasNSeal (single wall) vent lengths and components feature patented built in mechanical locking band and triple lipped directional gaskets. All pipes and components are engineered with smooth clean welds located 90 from mechanical locking bands. This construction feature allows for ease of installation. The air space between the inner and outer wall on FasNSeal W2 helps to reduce the clearance to combustibles in addition to creating a heat shield