Specifications. Two Color Rubber Mallet Hammer with PVC/TPR Handle. Size: 8, 12, 16, 24, 32oz. Instructions. hammer is a tool consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal (as with a forge), or to crush rock.