fully assembled board includes:
ATmega2561-16AI / ATmega2561-16AU (-40 bis +85°C), X1 crystal 16 MHz, X2 crystal 32.768 kHz (for asynchron timer)
header layout, schematics, programming tutorial, USB driver
Mini-USB cable
female connectors 2 pieces (2x15 pins) are also available
options:
ATmega2561-16 with 14.7456 MHZ crystal for serial communication (USART1 and USART2) without baud rate error
AVR
ATmega128 datasheet (pdf)
AVR
ATmega2561 datasheet (pdf)