The Swivel Coupler will fasten from 1-1/4" pipe (1.660" OD) to 2.050" OD truss tube. The Swivel-Coupler has wide wing nuts for fastening the clamp to the pipe or tube.
Minimum Size: 1.25" pipe, 1.66" OD pipe
Maximum Size: 1.5" pipe, 1.90" OD pipe, 2" OD truss tube