The Seiko 1F20 quartz watch movement is a two-hand (hour/minute) ladies’ caliber measuring 4½ × 5½ lignes, with dimensions of 10.00 × 12.50 mm, a thickness of 1.80 mm, and an overall movement height of 2.94 mm. It uses 90/45 hand sizes, contains 0 jewels, runs on a 337 battery, and includes stem part number 351-807, which features a 0.60 mm (tap 13) thread.
