Mega-Coupler has a 1/2″ Hex Head Bolt with The Light Source Wing Nut. Mega-Coupler has solid nut tabs that won’t 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 thick base.