This is an old iron tsuba( probably Muromachi era) that I believe is of the Katchushi school (sword smith tsuba). The iron has a dark patina showing a lot of age. It is almost round measuring 3 3/8 inches by 3 ¼ inches or 8.5 cm by 8.3 cm. The mimi (rim ) is round and the inner plate was attached to the inside of the rim at four places using a tongue in groove method. There is a sukashi carving of what could be a stylized rain hat on one side of the plate. This carving also serves as a hitsu-ana for a kozuka. This tsuba has not been papered as of yet. The overall condition is very good.