Ultimate Series toys are tough and long-lasting. Use interactively with one or multiple dogs. It can be used to play fetch or a tug toy. Great toy to entertain multiple dogs for hours. Soft edges won't hurt gums. This toy is rated at 9 on the Tuff Scale. Great for indoors. Washable. And floats. Ultimate construction features up to seven rows of stitching. The number and rows of stitching depends on the shape, size and style of the toy. Two directions of cross stitching hold the multiple layers together. Rows of stitching hold the webbing around the materials edge, and the toys' parts are sewn together with up to three rows of stitching. When possible, a protective webbing is added around the outer edge and sewn up to three more times. Tuffy toys can have up to four layers of material depending on the shape, size and style of the toy. Our Ultimate series can have up to two layers of luggage-grade material. Certain layers of material are coated with a layer of plastic to hold the material fibers together. Finally we use soft fleece for the outside layer. For our Ultimate series we add an additional layer of webbing, whenever possible around the outside edge to cover the seams of the toy. This is sewn multiple times, for added durability. Squeakers are sewn into material pockets inside the toy. This additional layer of safety can give you the time you need to safely remove the toy in the event your dog reaches the core of the toy.