See Arms & Armour of the Crusading Period, 1050-1350, Nicolle, figure 221 for a similar example. 2" diameter, 1 3/8" height, forged iron. Bun form with a matrix of diamond shaped lugs covering the surface. Specifically identified with the Crusades and capable of delivering a fatal blow to the lightly protected Saracens. Originally mounted on a hardwood haft. Rare and very seldom available.