25" Twisted Chews-Large Four Knot Cotton Rope is great for the heavy chewer. Twisted Chews ropes are made from 100% premium cotton rope to keep pets playing safer and longer. Rope toys help keep your dog's teeth and gums clean and healthy. Unlike humans, dogs only have two cones in their eyes, causing them to see a limited pallet of colors. Blue is the darkest color they can see and yellow is the lightest. By making our toys blue and yellow, your dog sees great contrast and can find them easier.