The membership certificates of the Penang Ghee Hin Kongsi, the Hai San Society and the Toa Peh Kong Kongsi form part of the secret society paraphernalia found in the William Stirling Collection; William George Stirling was the Assistant Protector of Chinese in Singapore from 1921 to 1931. The membership certificate of the Ghee Hin Kongsi is the one shown on the top left. On the bottom right is the membership certificate of the Toa Peh Kong Kongsi which had been in existance in Penang since 1854. On the bottom left is the membership certificate of the Hai San Society. The names of the four guards that were stationed at the cardinal gates of the Hung Lodge were written at the four corners of the certificate.
