The wheels turn towards each other. You try to put the windrows between wheels 1 & 2 and 3 & 4 although it is not absolutely necessary to do so.

Here is a you tube video of someone tedding alfalfa. Most tedders are made in Europe because they often need them to get hay to dry in their climate. I think Vermeer makes tedders. Here is an interesting Vermeer tedding video with larger models.

Jim