Standard threads: 1/2 NPT tapered threads, standard US. Size tapered threads, ensuring easy and fast installation. Advanced CNC precise machining minimizes leaking potential. All metal: made of stainless steel and brass and sturdy constructions, suitable for both plastics and metal shower heads. Large size: dimensions: 16"(l) x 1"(w) x 1"(h). Our 16-inch shower arm can work with 8-inch to 12-inch extra-large overhead shower, providing a large wall distance for a relaxing shower.