Text copied from TM 1985-6 (1953) :

Description: The incendiary grenade is made from an ordinary one-liter glass bottle, fitted with a metal pressure cap, and containing an inflammable liquid. A fuse match, protected by a canvas cover, is fixed to the side of the bottle by two rings of cord. To the top of the fuse is attached a fine cord, which, on being pulled, fires the fuse. To avoid accidental ignition by a chance drawing of the cord, the cord has a small wooden handle and is fixed to the neck of the bottle by a ring of thread.

Operation: Just before use, the wooden handle is freed by a light pull on the ring of thread which is securing it to the neck of the bottle. The handle is then given a sharp pull, and a small flame will appear at the lower end of the fuze. The bottle should then be thrown with force against the target. If the bottle is not thrown immediately, it may burst before reaching the target. A minimum of two seconds is given between the lighting of the fuse and the bursting of the bottle. The Italians consider the grenade to be a good weapon for defense against A.F.V's at close quarters.