"Red cash coins" (Traditional Chinese: 紅錢) are the cash coins produced in Xinjiang under Qing rule following the conquest of the Dzungar Khanate by the Manchus in 1757. While in Northern Xinjiang the monetary system of China proper was adopted in Southern Xinjiang where the "pūl" (ﭘول) coins of Dzungaria circulated earlier the pūl-system was continued but some of the old Dzungar pūl coins were melted down to make Qianlong Tongbao (乾隆通寶) cash coins, as pūl coins were usually around 98% copper they tended to be very red in colour which gave the cash coins based on the pūl coins the nickname "red cash coins". 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. The edges of these coins are often not filed completely and the casting technique is often inaccurate or the inscriptions on them seemed deformed.