The marking are hard to see on the SPAS-12 barrel because they are hid under the heat shield. They are (at least mine are) hard to photograph due to a weak stamping due to the taper of the chamber. Excuses in place, here are a few images along with what they say.
LUGI FRANCHI S.P.A. - BRESCIA - MADE IN ITALY
12 Ga - CHAMBERED 2 ¾ - CHROME - MOLY STEEL
CHAMBERED 2 ¾
(Remember this -- 3" shells may seem to fit, but this is a 2 ¾" chamber. Shooting 3" shells is very dangerous)