猿手 Sarude / Monkey Hand
What is Sarude in Japanese Katana terminology?
This is a decoration on the helmet gold (冑金 Kabuto gane), and it is a metal fitting for passing the ""Udenokio"" (a cord wrapped around the wrist to prevent the sword from leaving the hand). It is named because it looks like a monkey holding hands. When used for Hyogo Chain Tachi, it is characterized by being made of chain.