You would mount those to shoes. The slot would catch the rear edge of a quill pedal, typically. We rode with cleats like those before Look came out. I found them nerve-wracking, because to work, you had to tighten the toe strap, making quick exit tricky. I normally left at least one of my straps loose. I was glad when Look came out and glad once again when SPD came out. Sometimes I think SPD is Shimano's best invention ever.