As its name suggests this foot has rollers that roll against the fabric and act very much like the track on a bulldozer for sewing up and over heavy seams and uneven surfaces. Ideal for sewing heavy fabrics the rollers move freely between the foot and the feed dogs so that the foot rides easily over varying thicknesses. Also used to sew sticky leathers and vinyl.
(How can you possibly be without one?)
This foot is a Genuine Janome item - in Janome packaging.