Seiko Calibre 56 movement family

25 jewel versions have additional jewel bearings for the upper and lower arbor ports instead of bushings, reducing wear.

5601: 5601A

5605: 5605A

5606: 5606A: 23 jewels, 25 jewels. Time, date, and day, 3 hands: Hours, minutes, centre sweep seconds, date window, day window. Found in Lord Matics and SEIKO Automatics. Earliest known example: December 1967, serial number 7D1976, found in a 5606-7010.

5621: 5621A: 25 jewels. Found in King Seikos and SEIKO Automatics.

5625: 5625A, 5625B: 25 jewels. Found in King Seikos and SEIKO Automatics.

5626: 5626A, 5626B: 25 jewels. Found in King Seikos and SEIKO Automatics.

5641: 5641A: 25 jewels. Found in Grand Seikos.

5645: 5645A: 25 jewels. Found in Grand Seikos.

5646: 5646A: 25 jewels. Found in Grand Seikos.