The Weldmark by Superior WEM YV51 Acetylene/fuel gas Y connector is designed for use with two cutting and/or two welding torches at once, Cutting or welding torches, and approved for acetylene|fuel gas. It is constructed from brass, and has a maximum fitting pressure of 200psig. Technical specifications are CGA 023, and regulator side nut type B. The thread types are .5625-18 left hand UNF threads, with female threads on the regulator side, and male threads on the outlet side. Made in the United States.