Thailand or Siam. Japanese Bayonet Type 45 M1903. Marked with Siamese characters. Knife bayonet for use on the 8 mm M1903 Siamese Mauser rifle.  These were produced 1903–08, in Japan, at the Imperial Japanese Army Arsenal at Tokyo (Kowisikawa). The grip scales are secured with tiny screws set in escutcheons, as are found on early Japanese Type 30 bayonets. The characters on the ricasso say «R.S. 121» in Siamese, which represents the year 1903 on the Gregorian (western) Calendar.  «R.S. 121» is an abbreviation for Rattanakosin Sok 121.  This refers to the 121st year of the Rattanakosin Era, which began with the founding of Bangkok in 1782. The bayonet was re-designated Type 45 when Siam adopted the Buddhist Calendar in 1913. Year 2445 corresponds to 1903.