The Light Source Mega-Slim Coupler Metric M12 is a lower profile option for smaller light fixtures. It is half the size of the Light Source standard Mega-Coupler and weighs 30% less; yet fits the same as the Mega-Coupler. The Mega Slim 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 as well as a hex pocket for a metric M12 bolt. Includes metric M12 Flat Head bolt with nylock nut and spring washer. The bolt fits flush into the coupler.