The kerosang rantai/kerongsang brooch is a set of 3 brooches used by the Peranakan Straits Chinese ‘Nyonyas’ to fasten kebaya/baju panjang. Kebaya top has no button. Kerosang consists of three identical shapes and designs connected with chains. 
 
Brooch Dimension:
Height: 1.8 inches / 4.6 cm
Width: 0.4 inches / 1 cm