Drop-in resolution
ETA 2892-A2 vs Sellita SW300-1: do they swap?
Whether the ETA 2892-A2 and Sellita SW300-1 share a case, and what changes if you move between them.
Interchangeable. The ETA 2892-A2 and Sellita SW300-1 share the same 25.60 mm x 3.60 mm footprint and the same centre seconds, date at 3 layout, so one drops into the other's case with the correct dial and hands.
The ETA 2892-A2 is the slim upmarket automatic, base for many chronograph modules and higher-end pieces. The Sellita SW300-1 is the Sellita slim automatic, the drop-in alternative to the ETA 2892-A2.
Their published figures are the same to the tenth of a millimetre. 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.
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.