description: brand new, high quality feature: 1.Core maximum operating frequency of 72MHz 2. Contains flash program memory from 64K or 128K bytes 3. Using 2.0 3.6v power supply and I / O pins 4. Includes sleep, shutdown, and standby modes When the main chip STM32F103C8T6 development board is shipped from the factory, each test program is pre-programmed. After power-on, the LED lights will flash evenly to check whether the development board works normally. specification: Material: electronic parts Size: about 5.8x2.4mm / 2.28x0.94in Colour: Black Quantity: 1 note: Transition: 1cm = 10mm = 0.39inch. Due to manual measurement, please allow 0-1 for cm error. Make sure you do n'for t mind before bidding. Due to differences between monitors, the picture may not reflect the actual colors of the item. Thank you! The package includes: 1 x development board (not including other accessory demos in the picture.)