Vintage European and American cold wind twist twist winding ring niche design ins tide opening rings copper plated real gold

Here is a breakdown of the product based on the details you provided:

feature	describe
Finger circumference (inner diameter)	17-18 mm (opening can be fine-tuned)
weight	About 5-6 grams
material	copper
process	Color retention electroplating three layers of 18K thick gold
feature	No fading, no rust, anti-allergic; can be worn daily, no need to take it off for hand washing and bathing