 In July 1759 General Zhao Hui petitioned to the Qianlong Emperor to reclaim the old pūl coins and using them as scrap for the production of new cash coins, these "red cash coins" had an official exchange rate with the pūl coins that remained in circulation of 1 "red cash" for 2 pūl coins.As Zhao Hui wanted the new can coins to have the same weight as pūl coins they weighed 2 "qián" and had both a higher width and thickness than regular cash coins.Red cash coins are also generally marked by their rather crude craftsmanship when compared to the cash coins of China proper.