This mat is made for use with the Chain of 1000 (sold separately).  The mat is made of a heavy, high-quality felt with stitched edging to prevent fraying, and features a stitched-on elastic band to keep the mat together when rolled up.  It measures 10.2m (about 33.5') long and 23cm (about 9") wide, and comes with a cotton drawstring bag for storage.