Tuffy Dog Toy DuraForce BoneDuraForce Construction: Durability is created for each toy with multiple layers of flexible materials. The outer later is made from plastic coated polyester fibers that are woven into a thick mat for durability. This outer layer is equally thick as many multilayered durable dog toys. The inner layer is polyester to make the toy even more durable. Both layers are then cross stitched together. Tuff Scale: 9 Available in: Blue & Green Orange & Yellow Jr.