|Winding:||Automatic, Bi-Directional Automatic Winding|
|Diameter:||30.97 mm (12.5 ligne)|
|Rolex Cal. 3187 © Rolex||Complications:||24 Hour Hand, Date, GMT Hand, Hacking Seconds, Hand Winding, Independently-Adjustable 24 Hour Hand, Quick Date Correction|
|Hands:||Central 24 Hour Hand, Central Hour Hand, Central Minute Hand, Central Seconds Hand, Date Window at 3:00|
|Production: 2011 – Current|
Cal. 3187 was an automatic movement with date and independently-adjustable GMT hand. Introduced in 2011, it replaced Cal. 3186 in the oversized 42 mm Rolex Explorer II Ref. 216570 and continues in use to this day.
- Rolex Explorer II (2011-present), Ref. 216570
Like Cal. 3186, Cal. 3187 used an anti-magnetic Parachrom hairspring and Paraflex shock absorbers rather than the Nivarox spring found in Cal. 3185. But Cal. 3187 was larger, measuring 30.97 mm in diameter, to move the date window outward in the 42 mm case of the Explorer II. This was similar to the over-sized Cal. 3136, introduced two years before for the 41 mm Datejust II.
As oversized watches became popular in the 2010s, Rolex created a group of special oversized movements. Cal. 3132, 3136, 3156, and 3187 all have a 2.5 mm wider main plate, bringing the movement dimension to 30.97 mm. This is not well-documented, and many sources list these movements at the Rolex standard diameter of 28.50 mm. The difference is obvious at a glance, however, with the wider flange visible in Rolex promotional shots and in the watches themselves. This larger size allowed the date wheel to be enlarged, moving the date display 1 mm further from the center on the large Datejust II and similar models.
The movement can be manually wound with the crown in position 1. Rotate the crown clockwise to wind the mainspring.
The date wheel is advanced with the crown in second position (one notch out). Turn the crown counter-clockwise to advance the date wheel by one day.
The time is set with the crown in third position (pulled all the way out). Rotate the crown clockwise to advance the minute and hour hands and counter-clockwise to turn them backward.