Hello, Sorry for my bad english. I Recently had the opportunity to buy, not one, but TWO Omega Sensor Quartz Cal.1640 NOS (New Old Stock) . One of them had a little ink spot on the display, Cal 1640 will be changed by Omega, but the case is in mint condition, never worn. The second one is also in perfect condition, New of course...But has a little tiny spot inside on the crystal (that can be easily removed by a specialist. Here are the pictures of the Beauty.