The pink gold Audemars Piguet Royal Oak Offshore Barrichello II was launched in 2006, a tribute to its namesake in a limited edition of 500 pieces. One would be forgiven for mistaking this, the present watch Reference 26078, for simply one of those 500 – upon closer inspection one will notice that this is not the case. Instead of bearing the standard numbering (XX/500) the case back inscribed ‘PR01’ designating the watch as a prototype. The watch harbours a further secret: rather than being cased in pink gold, this prototype is cased in steel which has then been pink gold plated. These fascinating and rare details are confirmed in a letter that accompanies the watch, dated 2011. The letter clearly states that the watch is a prototype model made for exhibition and is not part of the standard Audemars Piguet collection. This is then a potentially a one-of-a-kind opportunity for any collector. Not only to acquire an incredibly rare and possibly unique variant of the Royal Oak – the ve...