This nylon cap fits on a post on the frame just below the triple clamps and comes in contact with the forks to limit the steering radius while protecting the chrome on the fork tube.  It is also used on some side stands to keep from scratching the paint on the swingarm while tyhe side stand is up. Used on some Sherpa T, Sherpa S, Campera, Alpina, Tiron, Lobito, & Matador models.