This is the original flesh tunnel style, the 'old favourite'. These are externally threaded ear tunnels with a flat flange in 316L Surgical Steel. A nice quality item with a precision thread. An excellent tunnel.
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.