Speedi-Products SM-26A90 07 7-Inch 26-Gauge 90-Degree Round Adjustable Elbow 7-Inch 26 Gauge Sheet Metal 90 degree adjustable elbows For use in HVAC appliance venting For use in commercial HVAC duct systems For turns through 90 degrees and are simple to adjust Seal joints with approved duct mastic sealants