EURO TOOL® rawhide mallets. Head is 1" wide, 2" long, made of tightly wound quality rawhide, with 8" wooden handle. A leather mallet is the traditional silversmith's tool for reshaping silver rings, smoothing and straightening deformed metal, and for stretching sterling silver ring shanks without leaving noticeable hammer marks. 
Leather mallets must be conditioned before first use, as they are soaked in varnish to stiffen the leather. To break in (or condition) your leather mallet: hammer it against a hard surface (large granite rock, a wall, concrete pavers, the concrete curb...) until the mallet softens. After this, the older and more beat up your mallet gets, the better it is for smoothing and shaping jewelry!