Miyota 9039 caliber: dimensions and drop-in group

Used in: the no-date member of the 90 series, popular in clean-dial microbrand watches.

The no-date sibling of the 9015 at 26.00 mm x 3.90 mm, sharing the same dial-foot location. It drops into a 9015 case as long as the dial has no date window, which is its whole point.

Drop-in group: Miyota 90 slim footprint (26.00 mm x 3.90 mm). 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.