ETA 2892-A2 caliber: dimensions and drop-in group

Used in: the slim upmarket automatic, base for many chronograph modules and higher-end pieces.

Same 25.60 mm diameter as the 2824-2 but only 3.60 mm tall, a full millimetre thinner. It is a slimmer platform, not a drop-in for a 2824 case, because the reduced height changes hand heights and case seating.

Drop-in group: 11 1/2 ligne slim automatic (25.60 mm x 3.60 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.