The Light Source Monstro-Coupler, Swivel, 3" to 2", Black

Standard Monstro-Coupler base with a 1/2-13 TPI threaded hole. Monstro-Coupler Base with 1/2" Countersunk hole. "CS" is at the end of the part number. Monstro-Coupler Size Chart (See PDF to download) The outside diameter is the distance across the pipe from outside to outside. The inside diameter is the distance across the inside opening of the pipe. The Pipe and Tube Sizing Chart is available to download as a PDF.