Selkirk 106060 Round Type B Gas Vent Chimney Pipe, 6" x 5', #6RV-5The RV line of Selkirk round vent pipe and fittings is designed for use on approved gas appliances in residential and light commercial and industrial applications. Round vents for large appliances will be found in the QC section which follows. Part No. 6RV 5 6" x 5' Lengths Pipe 5' Round Type B Gas Vent Easy to assemble and can be combined to obtain the required installation height Sectional overlap of 1. 5". Hence, net assembled length is 1. 5" less