The Omega Speedmaster 'Enamel Limited Series' was introduced in 2002 in celebration of Omega's new self-winding chronograph movement caliber 3303 - seen in this model as the luxurious 3320. A series of 99 pieces each was made in white, yellow and red gold, all featuring an enamel dial with painted numerals and the signature 'Broad Arrow' hands.Reference 3657.20.31 has a white gold case.
