Replacement nylon Centre for Raddog Training Dumbell with string

A nylon center with a string is used to train a calm and firm hold on the retrieve, without biting. As soon as the dog starts biting the nylon center or does not hold it firmly, you pull it out of its mouth using the string, which will cause the dog to lose its "prey". Over time, the dog will learn to hold the nylon center firmly and calmly, without biting