From the manufacturer:
ChiaoGoo needles are made of Moso bamboo, the largest and strongest bamboo in the world. The coloring is completely natural; no dyes or stains are used to achieve the warm brown shade. Some consumers appreciate the color as it provides contrast with the majority of shades of yarn. Circulars feature a metal join and clear, flexible cable. The cable itself spins freely so the cables do not twist as you knit. The connection between cable and join is ultra smooth. They have a nickel-plated, copper join. This package contains one pair of size 19/15mm circular knitting needles with a 40 inch cord. Imported.