The Light Source MLB3/8 Mega Coupler 3/8" Hex (Black)The Mega Coupler has a 1 2 1 1 4" Hex Head Bolt with The Light Source Wing Nut. Our Mega Coupler has solid nut tabs that wont break off. It uses standard 1 2 inch by 1 1 4 inch long hex head grade 8 bolts to secure your load. The bolt head locks into the hex milled pocket so that you can tighten the nyloc nut while the clamp is installed. The Mega Coupler fastens from (1 1 4" Pipe) 1. 66" OD to 2 " OD truss tube and has the industry compatible 14 mm