Features: Support for the IDE 1.0+ (OSX / Win / Linux) Power via USB or External Source - 5V or 7 -35V (automatic selection) On-board 500ma 5V Regulator Built-in USB(and serial debugging) 6 I/O Pins (2 are used for USB only if your program actively communicates over USB otherwise you can use all 6 even if you are programming via USB) 8k Flash Memory (about 6K after bootloader) I2C and SPI(vis USI) PWM on 3 pins (more possible with Software PWM) ADC on 4 pins Power LED and Test/ Status LED (on Pin0) Weight: 4g Package included: 3 x Development Board