what are they?
Spoiler alert: Amazon sells them. (That is how I discovered the name.)
I have been in garden centers often over the years and never saw one. I acquired them from an estate a couple of years ago. They are:
rotary tillers (with a broom type handle)
Applied testing: It does a nice job freshening up last year’s mulch and also works well mixing homemade compost with clay type soil.