This is the imitation leather case for my Kindle. It has a clasp with a button magnet buried in it. Eventually the magnet wears a hole in the fabric retainer on the underside of the clasp.
This Instructable will demonstrate using larger diameter shrink wrap tubing to cover the magnet and hold it in place while giving a neat, professional look.
Next to my thumb is some of the soft cloth that retains the magnet used in the clasp. The actual magnet is below my thumb. (I completed this project before I thought about making an Instructable from it.)