M241.  Signed and papered Akasaka tsuba.  7.4 x 7.6 x .45 cm.  The nakago hitsu-ana is.8 x 2.5 cm.  If I have this correct, the mei is Buko (Edo) Akasaka Ju Koyabashi Eiju, and maybe Eiju can be read as Shigemitsu also.  This tsuba comes with a Hozon paper from the NBTHK in Tokyo, dated 2006.  Excellent condition.  $795.