Drop-in resolution
Ronda 715 vs ETA 955.112: do they swap?
Whether the Ronda 715 and ETA 955.112 share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The Ronda 715 (26.20 mm x 2.50 mm) and ETA 955.112 (25.60 mm x 3.15 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 Ronda 715 is a very thin Swiss three-hand quartz movement, in slim quartz dress watches. The ETA 955.112 is a common Swiss three-hand quartz caliber, the ETA rival to the Ronda 515.
They differ in diameter (26.20 mm vs 25.60 mm), height (2.50 mm vs 3.15 mm), calendar layout (centre seconds, date at 3 or 6 vs centre seconds, date at 3), winding behaviour. A slim three-hand quartz caliber at 26.20 mm x 2.50 mm with a selectable date at 3 or 6. Thinner than the 500-series, it is its own 700-series footprint and pairs with the same-family 763.
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.