Extraordinarily well-matured single malt here from the Bunnahabhain Distillery, released by independent bottler Ferg & Harris. This expression was distilled in 1978 and left to mature for a massive 42 years, including a finishing period in a Pedro Ximénez sherry cask. Eventually, it was bottled at 48% ABV, with only 200 bottles produced. If incredibly old Islay is your thing, then this will very much be to your liking.