Up for sale is one of the rarest Speedmaster references: 3539.31.
Unlike its predecessor, the 3510.21, this reference has several upgrades. The crystal is sapphire instead of hesalite, the water resistance is increased to 100m, the bracelet is upgraded to a one of a kind hidden clasp bracelet unique to this reference, and the hour markers are applied instead of printed.
Case size: 39mm
Also this reference had a much more limited release and is incredibly difficult to find, especially as a full set.
Condition is close to mint with very little signs of wear. The sticker is still on the case back.
Comes with double box, warranty card dated 2008, and manual.