The Zacuto 3.5" ( 8.89 cm) Male/ Female Rod Extension (Black) is a 1 rod extension with 1/2" 13 threads. It has a male threaded connection on one end and female on the other end. The black anodizing rod is 0.59" ( 1.50 cm) in diameter with 2.36" (6 cm) spacing. This extension rod is lightweight and is made of 6061 aluminum.