This second-generation Rolex Day-Date features the caliber 1055 with a free-sprung balance and the 'Superlative Chronometer Officially Certified' designation on the dial. Shown here in rose gold with a Serpico Y Laino dial, it was introduced in 1957. It was succeeded by the 1800-generation circa 1959, with the 6611b reference also noted.
Movement Type
Automatic
Caliber
1055bJewels
25
Frequency
18000
Hands
Center Seconds
Shape
Round
Lug Distance
20.00 mm
Material
Rose Gold
Glass
Plexi
Diameter
36.00 mm
Water Resistance
50.00 m
Dial Color
Silver
