These were in use around 800 BC and were precise instruments of measure. Some were designed and used to help navigate ships by the stars. Other Kuei-pi disks were placed as pillows underneath the heads of the dearly departed to protect their journey into the other world. Set into a deep mat and framed they make exquisite wall hangings. Also people have used them as unique looking trivits for a special look at a special dinner occasion. They are all hand carved and made from real Jade. They come in several designs, each one is different. Approximate size is about 5.5" in diameter. Each one is different.