Tapering square seal made of buffalo horn. There are no inscriptions. The seal itself is round and consists of four characters surrounded by a border decorated with unknown objects. In the centre of the seal is a Yin and Yang symbol, which represents opposite forces that are actually complementary. The characters read from top to bottom ‘Yi You’ (益友) and from left to right ‘Tu Zhang’ (图章) which means ‘chop’. The seal most probably dates from the 1950’or 60’s. Height 5.0 cm. Width and depth 2.4 cm.