How would you use it?

It for an industrial machine according to the various descriptions....you could never fit the plastic circles over the head of your machine......the plastic rings are supposed to help push the leather or vinyl smoothly under the foot.
So the outside of the circle of plastic runs against your fabric.....old way of having a "walking" foot on an industrial machine....still don't know how it fit on those machines....

I was told to use Heat 'n' Bond for a T-shirt quilt. Wrong stuff. The presser foot would not slide on it and it wouldn't slide under the presser foot because it was sticking to the machine bed on the left side. I had to put a piece of trash fabric on the machine bed, sew a line of a few inches and then re-position the trash fabric. And be careful that I didn't sew the trash fabric into the seam. What a pain. This item may have helped me, but of course my machines are not in the list that would accommodate it.

My mom taught me when learning to sew: If the fabric to sew sticks [she was sewing vinyl], use a piece of tissue wrapping paper under the sticky fabric. You can sew right through that and it easily tears off.

I used this method when I was birthing quilts and the batting was the bottom layer. My batting kept getting stuck in the feed dogs and if I put it on top it would catch on the presser foot. I was so glad once I learned to use binding and no longer had that problem.