The (single) katahitsu ana 片櫃仕立 has a yamagaane 山銅 insert.
The dimensions are 85mm x 84mm. The fukurin is 5mm thick, the shinchu plate is 2.5mm thick.
The theme is described as Unryū 雲龍図鐔. The name Unryū means literally “cloud dragon”. In this design the “Cloud Dragon” is winding it’s way around the tsuba’s mimi through the clouds.  According to legend, “A dragon summons a cloud, a tiger invites the wind”. The dragon and the tiger have traditionally represented something or someone wielding great importance. In the Sengoku, or Waring States period for example, Uesugi Kenshin was known as “The Dragon” and his old rival Taked Shingen, was known as “The Tiger”. They engaged in battle several times at Kawanakjima and their battles were perceived as “fights to the death” between a dragon and a tiger. Unryū refers to the stage when a man or woman of special ability applies their talent, and becomes successful. It is natural that once he or she achieves notable success at a high level, regardless of their specialty or field, rivalries and jealousies will emerge, leading to a host of potential conflicts. These kinds of situation are compared to the clouds, the wind, or a storm.
This dragon has been produced by a treatment known as yakite kusarashi 焼手腐らし, a surface design or finish that has been created by acid treatment. Yakite-kusarashi comes from Yakite 焼手 (burnt, freshly baked) kasarasu 腐らし (to spoil; to rot; to corrode) thus producing a surface treatment or finish that is made by acid etching. This technique was often used by the Hôan and Hirata artisans, amongst others.
Thank you for reading.
 Samurai Fighting Arts: The Spirit and the Practice By Fumon Tanaka