Sellita SW290-1 caliber: dimensions and drop-in group

Used in: the automatic small-seconds caliber with the sub-dial at 9, in dress and pilot watches.

An automatic 11 1/2 ligne movement with small seconds at 9 and date at 3, at 25.60 mm x 5.60 mm. It shares the SW260-1 footprint but places the sub-seconds at 9, so each needs its own dial layout.

Drop-in group: 11 1/2 ligne automatic small seconds at 9 (25.60 mm x 5.60 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.