First Rolex Day-Date movement, introduced 1956. Automatic with bidirectional winding, COSC chronometer-certified. Used in first Day-Date models (refs 6510, 6511, 6611, 6612, 6613). Featured improved balance wheel over earlier calibers.
Movement Type
Automatic
Jewel Count
25 jewels
Power Reserve
48h
Frequency
18,000 vph (5 Hz)
Diameter
28.5mm
Height
7mm
Rotor Type
central_rotor
Winding
automatic_bidirectional
Shock Protection
kif
