Seiko Calibre 66 movement family

Designed by Suwa Seikosha.

66A (436/4361), Seiko Sportsman

66B

6601A (245/2451), Seiko Sportsmatic

6601B

6602 (957), Seiko Sportsman

6606A/410, Seiko Sportsmatic 5

6618A, Seiko Sportsmatic 5

6619A. Found in watch for blind people.

6640A (375/DT731). Found in Disney Time watches.

6660A, 21 jewels.