The Light Source Mega-Coupler, Aluminum Finish Minimum Size 1.25" pipe, 1.66" OD pipe Maximum Size 1.5" pipe, 1.90" OD pipe, 2" OD truss tube Safe Vertical Working Load 1,100 lb 500kg Hardware Standard hardware - 1/2-13  1 1/4" Hex Head grade 8 zinc plated steel bolt with nylock nut 1" Belleville Washer Weight 1.2 Pounds