The SEPPA (切羽) are washers above and below the TSUBA (guard) to tighten the fittings. there are 4 kind of SEPPA available here, they are all made of brass.
Brass Seppas Sword Fittings for Samurai Japanese Katana Wakizashi TantoMaterials: BrassSize: 4.3*2.6 cmUses: Katana / Wakizashi / Tanto SwordsNOTE: Click HERE to choose other mountings...