Drop-in resolution
ETA 955.112 vs Ronda 705: do they swap?
Whether the ETA 955.112 and Ronda 705 share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The ETA 955.112 (25.60 mm x 3.15 mm) and Ronda 705 (26.20 mm x 2.50 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 ETA 955.112 is a common Swiss three-hand quartz caliber, the ETA rival to the Ronda 515. The Ronda 705 is a slim no-date member of the Ronda 700 quartz family.
They differ in diameter (25.60 mm vs 26.20 mm), height (3.15 mm vs 2.50 mm), calendar layout (centre seconds, date at 3 vs centre seconds, no date, slim), winding behaviour. A Swiss three-hand date quartz caliber at 25.60 mm x 3.15 mm sharing the 11 1/2 ligne diameter. It is not a mechanical donor: replacing an automatic with it changes power source and hand heights entirely. It competes with the Ronda 515 at the same diameter.
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.