Stanhopes are optical devices that allow you to view a micro photograph without using a microscope.
This particular one is a writing utensil with a Vatican (Roma) image. It is probably from the pontificate of Pope Pius XI.
The Collection has several stanhopes. Another one from the era of Pius XI is a pipe with his image on it. There are also stanhopes from the pontificates of Saint John XXIII, Blessed Paul VI and Pope Pius XII.
Stanhopes were souvenir items sold in Rome at many different shops.