That's right, recycled tires form the "spine" of these bags, and they come from canine wheelchairs returned to my employer, Eddie's Wheels for Pets in Shelburne, Mass. I call them "Pocket Wheels" because they are not like a "book" at all! Heavy duty industrial look with polypropylene webbing, mesh, grommets, rivets, #10 metal zipper with double pulls, and bike gear on one side. The other side features a pocket. No pockets inside. Looks fantastic on all ages and goes with almost anything. Mesh is available in tan mix, red, white, and black (see other listing for black pix).