Omega Speedmaster Professional Moonphase ref. 3876.50.31, introduced in 2003, is driven by the hand-wound caliber 1866, which includes a moonphase and a pointer-date at 12 o'clock. This version comes on an alligator strap.
Movement Type
Manual Chronograph
Caliber
1866Jewels
17
Reserve
45
Frequency
21600
Hands
Small Seconds
Shape
Round
Lug Distance
20.00 mm
Material
Stainless Steel
Glass
Sapphire
Diameter
42.00 mm
Water Resistance
50.00 m
Dial Color
Black
