Thiss gimmick has the exact appearance and size of a real hammer. Because it's constructed with very light latex it can be thrown to the audience.
Picture this, you speak about classic magicians, and the fact that they threw a flower to the audience in every show, and the spectator that received the flower was usually designated as the magician's assistant for the trick. Then you explain that you are not a classic magician, so you brought the hammer, and then you toss it to the audience. Remarkable gag that will remain in the audience mind for long time.