This is the Adafruit METRO with headers. It comes with headers soldered on. It's a fully assembled and tested board with through-hole headers attached. If you don't want a Metro with the headers attached for super-slimness, check out our Metro without Headers.

METRO is the culmination of years of playing with AVRs: we wanted to make a development board that is easy to use and is hacker friendly. At the heart is an ATmega328P, with 32KB of flash and 2KB of RAM, running at 16 MHz

• Power the METRO with 7-9V polarity protected DC or the micro USB connector to any 5V USB source. The 2.1mm DC jack has an on/off switch next to it so you can turn off your setup easily. The METRO will automagically switch between USB and DC.
• METRO has 19 GPIO pins, 6 of which are Analog in as well, and 2 of which are reserved for the USB-serial converter. There's also 6 PWMs available on 3 timers (1 x 16-bit, 2 x 8-bit). There's a hardware SPI port, hardware I2C port and hardware UART to USB. Logic level is 5V but by cutting and soldering closed a jumper, you can easily convert it to 3.3V logic
• USB to Serial converter, there's a hardware USB to Serial converter that can be used by any computer to listen/send data to the METRO, and can also be used to launch and update code via the bootloader
• Four indicator LEDs, on the front edge of the PCB, for easy debugging. One green power LED, two RX/TX LEDs for the UART, and a red LED connected to pin PB5
• Easy reprogramming, comes pre-loaded with the Optiboot bootloader, which is supported by avrdude and only uses 512 bytes.
• Works with all Adafruit shields

We also include 4 rubber bumpers to keep it from slipping off your desk. Metro shown with our 12x capacitive touch shield attached just to demonstrate the headers, but that shield is not included!