Double flared natural blue sandstone tunnels. Blue sandstone is a dark blue stone like the night sky and it is full of tiny shining specks of colour like stars... Absolutely stunning. There is no 12mm size of this particular item as it was was manufactured using American Gauge sizes. The closest to 12mm is 1/2" which is 13mm.
Unless clearly stated otherwise,
the price is for one piece, not a pair.