SW 400 is a caliber manufactured by Sellita

The SW 400 is a self-winding Swiss movement introduced in 2014 to meet the growing demand for larger watch cases. It is based on the proven SW 200-1 (and thus indirectly on the ETA 2824-2), but differs in that it features an additional spacer ring that increases the diameter from 25.6 mm to 31.00 mm (14''').