It's a hollow steel mallet with a compartment that slides out of the head.
Billet does not rhyme with ballet, Bouquet, wallet, mallet, chalet.
She gave him an axe, a mallet, and two wedges.
" Then he gave him a glass axe, a glass wedge, and a glass mallet.
He, however, had to serve the cat, and chop some wood every day, and to do that, he had an axe of silver, and the wedge and saw were of silver and the mallet of copper.