1, 2 and 3 indicate the presence or absence of the central discharge hole (Flow technology). What guides the choice is the rotation of the pelvis and the flexibility of our body.
For those cyclists with excellent pelvic rotation, size 3 is recommended, while for those with less flexibility, size 1 is recommended.
1: indicates closed saddle, that is, the absence of a hole.
2: indicates the presence of a smaller hole called "Flow".
3: indicates the presence of the hole called "Superflow" (the widest one).