BUILT FOR MODERATE CHEWERS Our best-selling customizable puzzle and treat toy is designed to be filled with a dog's favorite kibble or treats. Toppl's soft, rounded inner 'teeth' contain a contoured cavity to hold treats in place until your dog nudges them out. To change up the challenge, simply connect the XL and Large or S mall and L arge together . Pair with Toppl Stopper to block Toppl's side hole to keep liquids safely inside.