The PROCYON toy egg is similar in principle to a Treibball. It is extra large so that the dog does not carry it with its mouth, but drives or rolls it.Unlike a normal Treibball, however, the egg does not simply roll straight ahead, but changes direction unpredictably due to its egg shape. It is therefore suitable for slightly more advanced players who are already good at handling a Treibball.The egg is made of hard plastic and is therefore not damaged so quickly by attempts to bite it.