The KONG dental toys with the unique, patented Denta-Ridges reduce plaque and food debris while providing a gentle abrasive cleaning and conditioning of teeth and gums while providing entertainment for long periods of time. KONG Easy Treat can be used inside the grooves if desired.Small ' for dogs 1-20 poundsMedium ' for dogs 15-35 poundsLarge ' for dogs 30-65 poundsExtra-large ' for dogs 60-90 pounds