Michelangelo's "River God" seen here was on loan to the "Cinquecento" exhibit
from the Academia. It is made of clay mixed with some other materials and fibers, and worked around an iron core.
The sculpture was originally painted to look like marble, but has been restored to its original appearance.
This "River God" is similar to the river gods in the New Sacristy in San Lorenzo.

Just behind Michaelangelo's sculpture can be seen Pontormo's "Deposition"
made for the Capponi Chapel in Sta. Felicita in Florence.