Seiko 4R39

The Seiko 4R39 is an automatic movement belonging to the 4R family, serving as a variant of the 4R35 base caliber. As with other 4R movements, it is manufactured in-house by Seiko and features hacking and hand-winding functions. The 4R family is known as Seiko's mid-range automatic caliber series, used across the Seiko 5 Sports and Presage collections. This caliber remains in production.