Before, we used original ST chips. Due to the change in cost, we used ST compatible chips, they are fully compatible with ST chips and greatly reduces the cost of the module,can spend the least money to buy the same goods.Change by--2022 May 10 If you need ST chip, please don't buy it, this is not ST, this is a compatible version Features: 100% high quality! STM32F103C8T6 ARM STM32 Minimum System Development Board Module For Arduino Specifications: Model: STM32F103C8T6. Core: ARM 32 Cortex-M3 CPU. 72MHz work frequency. 64K flash memory, 20K SRAM. 2.0-3.6V power, I/O. Reset(POR/PDR). 4-16MHz crystal. Size: 5.3cm x 2.2cm Color: Blue

Before, we used original ST chips. Due to the change in cost, we used ST compatible chips, they are fully compatible with ST chips and greatly reduces the cost of the module,can spend the least money to buy the same goods.Change by--2022 May 10.