copper equal diameter double outer External thread 1/2 conversion 1/4’ Variable diameter 3/8’ turns 1/8’ joint 1 inch 4/3
https://www.vogueparade.com/shopping/EN/200282142/1/1005001717696979/copper-equal-diameter-double-outer-external-thread-12-conversion-14-variable-diameter-38-turns-18-joint-1-inch-43//