The distillery people explained that this is a triples matured expression. Whilst matured for 12 years in the (for Glenkinchie) standard second and first fill Bourbon casks, they transferred the Whisky into freshly heavy charred casks and then into sherry casks for rest of the maturation.
There is no age statement on the bottles.
For me that one beated the 12year old, the distillers edition and even the 24 year old while in the VIP tasting at the distillery. Only the direct cask sample of an 1988 sherry cask Glenkinchie in cask strength was better (by far :-).