4" x 18" Round Pipe, Type B Gas Vent

Features

• 3 to 12 in pipe and fitting couplers overlap 1-3/8 in when joined together; therefore, assembled length is 1-3/8 in less than listed length
• The allowable min clearance to combustibles is 1 in
• A full set of installation instructions are supplied with caps and supports
• For type b gas vent system
• 0.018 in G90 galvanized steel outer
• Aluminum inner