The Light Source MSCB-1/2CS - Mega Slim Coupler with 1/2" Flat Head Bolt - Black Anodized Minimum Size 1.25" pipe, 1.66 OD pipe Maximum Size 1.5" pipe, 1.90 OD pipe, 2.050" OD Truss Tube Safe Vertical Working Load 500 lbs Hardware 1/2" Flat Head Countersunk Bolt Weight 0.65 lbs.