In China, ring sizes are divided into Hong Kong version and mainland version. In the Hong Kong version, the ring 13 ring circumference is 55mm, the diameter is 16.5mm; In the mainland version, the ring No. 13 has a circumference of 53mm and a diameter of 16.9mm. There are some brands of ring size will be different, so when you buy a ring, you must first consult customer service or shopping guide, understand the size of the brand ring, and then choose.
