Released alongside the series 3 1 BTC 2013 coin, these were sold in rolls of 12. Unlike their 1 BTC counter-parts, these (like the 0.1 BTC coin) series 3 holograms do not utilize ‘laser rimming’ as a security measure.
It is known that at least 42 additional 0.5 BTC coins are later funded (LF) in 2015 and 2016. It is unknown how many of them are
of this silver variety. It is unknown if any LF ‘Silver Error’ coins exist.