“In addition we produced 45 halfBTC coins with the series-2 sticker which were not numbered into these rolls. These were available to those who made initial orders, though are no longer available for sale”.
The coins were created to avoid wasting leftover series 2 holograms. They were sold in rolls of 12.
*It is assumed that none of these coins have been opened, as those receiving them likely understood their rarity and only two out of all silver 0.5 BTC coins are known to have been opened.