✦ Treats can be hidden in all sides of the knot, so your pup has to roll the knot in order to find all the treats ✦ Covered with crinkle paper for extra stimulation ✦ Reinforced and strengthened with nylon lining for longer lasting quality ✦ Beautiful design and neutral colors to fit into any home aesthetic ✦ Made with non-toxic materials. Tested with ASTM F963 (US) toy safety standards. ✦ Size: 5" diameter / 12.7cm diameter