Drop-in resolution
Miyota FS00 vs Ronda 5040.B: do they swap?
Whether the Miyota FS00 and Ronda 5040.B share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The Miyota FS00 (28.60 mm x 4.85 mm) and Ronda 5040.B (28.60 mm x 4.40 mm) are near in size but differ in height, dial feet or layout, so moving between them means a new dial, hands and often a case adjustment.
The Miyota FS00 is a Japanese quartz chronograph module, an alternative to the Ronda 5030.D. The Ronda 5040.B is a full-feature Swiss quartz chronograph with a big date, in premium quartz chronographs.
They differ in height (4.85 mm vs 4.40 mm), calendar layout (chronograph, sub-dials, date vs chronograph, small seconds, 1/10s, 30min and 10h counters, big date), winding behaviour. A quartz chronograph at 28.60 mm x 4.85 mm with sub-dials and a date. It competes with the Ronda 5030.D on size but has its own sub-dial layout, so their dials are not interchangeable.
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.