Sintron MEGA 2560 R3 ATmega2560 - Arduino MEGA 2560 R3 Including USB Cable + Reference PDF Files for Arduino's IDE (Mega 2560) (1) Microcontroller:ATmega2560 (2) Digital I/O Pins:54 (of which 14 provide PWM output) (3) Flash Memory:256 KB (ATmega2560) of which 4KB used by bootloader (4) Clock Speed:16 MHz (5) After you purchase , just send an email to us with title "require Arduino pdf files for starters " , then we will show you how to access these PDF documents . so you can save a lot of time searching for these!