It is a metal coating worn in front of the chest or breastplate.
[1]: 320 [2]: 802 The Kakawin Ramayana (c. 870 AD), which is the Javanese version of Valmiki's epic Ramayana (c. 500 BC), mentions clothing and armor that reflect the era.
A member of the royal family is said to wear crown, padaka (collar, medallion, or breastplate), karambalangan (girdle or plastron) and use gold-plated armor even in battle.
[5]: 187 Emperor Raden Wijaya in that kidung was recorded using golden karambalangan manik.
[5]: 105 In the Kidung Sundayana, it is written that Gajah Mada before the Bubat tragedy wore a karambalangan (a metal plate on the front of the chest—breastplate) decorated with gold emboss, armed with a gold-plated spear, and a shield decorated with diamonds.