====== Rolex 6620 ======
**Cal. 6620** (and the similar **Cal. 6621**) were [[quartz movement]]s produced by [[Rolex]] between [[1987]] and [[2015]].

===== History =====
Rolex was part of the consortium that created the [[Swiss]] [[Beta 21]] movement, which Rolex sold as Cal. 5100 in the limited-production [[Rolex Date 5100|Date 5100]] watch. But even while supporting the [[Centre Électronique Horloger]], Rolex began investing in their own movement operation. The resulting Cal. 5035 and Cal. 5055 (day/date) were launched in [[1977]] in the [[Rolex Oysterquartz]] watch. These would remain in production until [[2003]] with no direct replacement.

Rolex developed a similar movement for ladies watches. Cal. 6035 measured 19.79 mm in diameter and 5.00 mm thick, the same dimensions as their automatic movement. Although some prototypes were built, this movement never reached series production.

Rolex created a time-only movement with no seconds hand, Cal. 6620, for the [[Rolex Cellini|Cellini]] line. Based on Cal. 6035, this new Cal. 6620 finally reached production in [[1987]]. It was a slim movement, measuring 19.80 mm diameter by just 2.5 mm thick. The similar Cal. 6621 was introduced in [[1990]]. Together, over 100,000 examples of Cal. 6620 and 6621 were produced before Rolex exited the quartz watch market after [[2015]].

Rolex also produced a model with a seconds hand, Cal. 6623.

Cal. 6620 features 8 jewels and operates at 32 KHz. It uses a stepper motor that operates once every 10 seconds.

===== See Also =====
  * [[Beta 21]] - The basis for the Rolex Cal. 5100 quartz movement
  * [[Rolex 5035]] - The only other Rolex quartz movement


{{tag>Quartz_movements Rolex_calibres}}