If the number 12 ring is purchased in the Chinese market, it will generally be divided into Hong Kong version size 12 and Mainland version size 12. The circumference of the ring number 12 in the harbor code is 54mm, or 5.4 cm; The diameter is 16.2mm, or 1.62 cm. The circumference of the number 12 ring in continental code is 52mm, or 5.2 cm; The diameter is 16.6mm, or 1.66 cm.
