TThe Mega-Slim Coupler is a lower profile option for smaller light fixtures. Although it is half the size and weighs 30% less, it fits the same as the regular Mega-Coupler. The Mega-Slim Coupler will fasten from 1-1/4" pipe (1.66 OD) to 2.050 OD Truss Tube. It has a wide wing nut for easy fastening of the coupler to the pipe or tube.