Mammoths Flossy Chews Extra! Newest design, all new, colors material and texture made from premium materials in fun shapes and colors dogs love. 3 Sizes to select from. The outer core is made from a poly cotton woven sheath and the inner core is made from poly cotton woven fibers. EXTRA toys are tougher than any standard rope chews and made more durable for strong chewers. Rope fibers floss dogs teeth as they chew and play. Great for tugging and chewing.