Rolex 3155

	Brand:	Rolex
	Family:	Rolex 3100 Family
	Height:	6.45 mm
	Jewels:	31
	Reserve:	48 hours
	Frequency:	28,800 A/h
	Winding:	Automatic, Bi-Directional Automatic Winding, Central Rotor Automatic Winding
	Diameter:	28.50 mm (12.5 ligne)
Rolex Cal. 3155 © Rolex	Complications:	Date, Day, Hacking Seconds, Hand Winding, Outer Day Wheel, Quick Date Correction, Quick Day Correction
	Hands:	Central Hour Hand, Central Minute Hand, Central Seconds Hand, Date Window at 3:00, Day Window at 12:00

Distinguishing Technical Characteristics
Central-Rotor Automatic Balance Bridge Microstella Balance Balance, Balance at 6:00
Production: 1988 – 2019
1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s

Cal. 3155 is an automatic movement with day and date used in the famous Rolex “President” Day-Date watch from 1988 through 2019. It was launched in 1988 in Ref. 118000, replacing Cal. 3055 in the Day-Date. The Day-Date was updated in 2000 but continued to use this movement, even as the Day-Date II launched with the larger Cal. 3156. Cal. 3155 continued in use in the 36 mm Day-Date until 2019 when the new Day-Date 36 with Cal. 3255 was introduced.

• 1988-2019 Rolex Day-Date, Ref. 118000, 118205, 118206, 118208, 118235, 118238, 118239

Note that many sources list the height of Cal. 3155 as being 6.00 mm (the same as the base Cal. 3135), the official Rolex parts document shows it as 6.45 mm.

Parachrom Update

Cal. 3155 was updated with the Parachrom hairspring between 2008 and 2010 but continued to use the Kif Elastor anti-shock device, unlike other Parachrom movements.