This is 12 inch nagasa tanto. Steel is pattern-welded 1050, 15N20 and 1095 in a straight laminate (itame). Water quenched. The hamon is made to look like a wave (nami). The saya is lacquered with silver gilding and horn koiguchi. The fittings are copper with a hammered (tagane) pattern. Traditional cotton tsuka-ito.