Classification According to Shape:

The followers contain different shape that remains in contact with cam.

Knife-edge Follower:

This kind of follower is shaped in the form of knife edge. It is illustrated in

Figure (a). It's utilized is restricted in practice because knife edge wears out in short period & after that it need to be replaced.

Roller Follower:

This kind of follower consists of a cylindrical roller that is free to rotate around a pin joint. It is illustrated in Figure (c). This kind of follower is broadly used.

Flat Faced or Mushroom Follower:

This kind of follower either consists of flat surface or spherical shaped surface. this is illustrated in Figures (b) & (d).