What's in David's hand?

A new study of Michelangelo's David concludes that the hero holds a "secret weapon in his right hand." A paper on the subject was presented at "Florens 2010: The International Week of Cultural and Environmental Heritage," a three-day tribute to the masterpiece.

The object, according to experts, is part of a fustibal, or staff sling, with a leather strap attached to the end. David holds the handle, which would have been mounted to a staff, in his right hand, while the leather straps trails across his back. The weapon would have been used to throw stones.