The Light Source Monstro-Coupler, 6" Pipe, Black

Standard Monstro-Coupler base with a 1/2-13 TPI threaded hole. "CS" is at the end of the part number. The inside diameter is the distance across the inside opening of the pipe. (See the Download PDF Section under the product description.) The Monstro-Couplers are designed to fit pipes larger than the standard theatrical battens.