Caliber reference
Seiko 4R34 caliber: dimensions and drop-in group
The published footprint of the Seiko 4R34 and which movements share it.
Used in: the branded Seiko caller-GMT automatic, the retail version of the NH34.
The branded Seiko GMT at 27.40 mm x 5.32 mm that the NH34 copies, with a 24-hour hand and date at 3. It shares the NH3x footprint and stem, so it interchanges with the NH34 within a GMT dial.
Drop-in group: Seiko NH34 / 4R34 GMT footprint (27.40 mm x 5.32 mm, GMT hand). Matching diameter and height is necessary but not sufficient. A donor is only a true drop-in when the dial-foot positions, hand-hole sizes, stem length and calendar layout also match. Two movements can share a case and still need a new dial, re-broached hands or a cut-to-length stem.
Drop-in and related calibers
Donor movement for Seiko 4R34drop-in lookup
Seiko NH34 (TMI NH34A)same footprint (27.40 mm x 5.32 mm)
Seiko NH34 (TMI NH34A) vs Seiko 4R34drop-in comparison
Miyota 8215 vs Seiko 4R34drop-in comparison
Miyota 8205 vs Seiko 4R34drop-in comparison
Miyota 821A vs Seiko 4R34drop-in comparison
Miyota 9015 vs Seiko 4R34drop-in comparison
Miyota 9039 vs Seiko 4R34drop-in comparison