Mainspring for wrist watches with manual winding.
Suitable for the following calibres:
ETA: 1256, 1257, 1258
Eterna: 1237T, 1239T, 1243T, 1246T, 1247T, 1248T, 1249T, 1252U, 1253U, 1254U
Girard Perregau: 45, 47
Hamilton: 1248, 659, 660, 672
LIP: R107.1, R122
Attention: This spring is not wound up.