Medieval Combat Ultimate Hand Forged Shield Boss Umbo - Tophatter's Inc. Weapons Store OnlineA shield boss is a round, convex or conical piece of material at the center of a shield. The boss was originally designed to deflect blows from the center of round shields, though they also provided a place to mount the shield's grip. This 16 gauge combat grade shield boss allows for you to create your very own function battle ready shield. Forged iron this umbo comes with 6 pre drilled holes for easy mounting. This quality functional piece boss.