Seiko 4R37

The 4R37 is an automatic movement manufactured by Seiko and part of the 4R family, derived from the 4R35 base caliber. Introduced in 2012, it remains in production and features a complication—most commonly a day-date display—while maintaining the 4R platform's signature hacking and hand-winding functions. As an in-house caliber, it represents Seiko's entry-level mechanical offering, commonly found in Seiko 5 Sports and Presage models.