Patent ID: 8398123

Claim:
A duct coupler comprising: a generally tubular body having a first end and a second end, said generally tubular body having a circular cross-section, said body having an interior passageway extending from said first end to said second end, said first end having a plurality of threads formed on an interior wall and extending inwardly from said first end, said second end having a plurality of threads formed on the interior wall of said tubular body and extending inwardly formed said second end, said tubular body having an outer surface, said outer surface being radially indented around a circumference thereof centrally between said first end and said second end, the threads at said first end and the threads at said second end of said body being square threads, said body having an outer surface with a first lip extending longitudinally outwardly of said first end and a second lip extending longitudinally outwardly at said second end, said tubular body having an outer diameter at said second end of said body, said first lip having a circular cross-section with an outer diameter greater than said outer diameter at said first end of said body, said second lip having a circular cross-section with an outer diameter greater than said outer diameter at said second end of said body.