The Kerongsang Kebaya Peranakan, that is. (I think some call it Kerongsang Rantai)
The ladies who donned the Kebaya Peranakan would need to garnish the front with a three-piece brooch that was intra-linked with a chain (usually of gold or silver). The brooches came in a huge variety of intricate and exquisite designs and were often adorned with precious stones of various colors too.
This fashion accessory-cum-pin fastener was an essential item to complete the Kebaya outfit. But as these were expensive pieces of jewelry, the ladies in less well-off families could only afford a set in their lifetimes – often the relatives would mutually exchange among themselves for different festive occasions (usually weddings).