What Were Ancient Acupuncture Needles Like?

If acupuncture is thousands of years old, what did they use for needles back then? Early on, stone tools were used for medicinal purposes and over time were formed into thin needles. Next they were made from bone and bronze. In the 2nd century BC, needles began to be made using gold and silver. Today, we use stainless steel needles that are sterile, filament-thin, flexible, single-use, and relatively painless. They are properly disposed of after every treatment.