Four Chinese characters (seal script) Zheng He Tong Bao (wide rims type) / Blank. 29mm, 8.55 grams. Issued in 1111-1117 AD. Schjoth #-(638 var); Hartill 16.435.

In the 1st year of the Zhenghe era (1111) the Emperor issued a decree that the older larger 10-cash coins were to be denominated to 3-cash. The new 3-cash coins (like this coin) of the Zhenghe type were also cast. 

The Song dynasty was a Chinese dynasty that ruled from 960 to 1279 and is renowned for its economic prosperity, technological innovation, and cultural achievements. Divided into the Northern Song (960–1127) and Southern Song (1127–1279) periods, it oversaw major advances in printing, gunpowder, navigation, and commerce. The Song economy was among the most developed in the medieval world, with thriving cities and extensive domestic and international trade. Despite its cultural and economic strength, the dynasty ultimately fell to the Mongols under Kublai Khan in 1279.

This coin is unconditionally guaranteed to be authentic