The Mega 2560 is an update for Arduino Mega, which it replaces. 
The board is a microcontroller board based on the ATmega2560-16AU .It has 54 digital input/output pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields designed for Arduino Duemilanove or Diecimila. 
Product Summary: 
CH340G replace the Atmega 8U2/16U2 
CH340G Driver Download link, please copy the link and paste in browser:www.5v.ru/ch340g.htm

Specifications: 
Microcontroller:ATmega2560 
Clock Speed:16 MHz 
EEPROM:4 KB 
SRAM:8 KB 
Flash Memory:256 KB of which 8 KB used by bootloader 
Operating Voltage:5V 
Input Voltage (recommended):7-12V 
Analog Input Pins:16 
Digital I/O Pins:54 (of which 14 provide PWM output) 
DC Current for 3.3V Pin:50 mA 
DC Current per I/O Pin:40 mA 
Size:100*55mm


Package Included:
1 x FOR Arduino Compatible Atmega2560-16AU CH340G ATMEGA 2560 R3 Board Mega2560 R3
1 X USB Cables