Specification : Microcontroller: ATmega328 (DIP Package) Operating Voltage: 5V Input Voltage (recommended): 7 ~ 12V Input Voltage (limits): 6 ~ 20V Digital I/O Pins: 14 (of which 6 provide PWM output) Analog Input Pins: 6 DC Current per I/O Pin: 40 mA DC Current for 3.3V Pin: 50 mA Flash Memory: 32 KB of which 2KB used by bootloader SRAM: 2 KB (ATmega328) EEPROM: 1 KB (ATmega328) Clock Speed: 16 MHz Size: 75 x54 x15 mm (2.95 x2.13 x0.59 #34;) Envionment Friendly: Rohs Compliance Source : https://www.dfrobot.com/product-838.html