The Adafruit Feather are a complete line of development boards from Adafruit Industries that are both standalone and stackable. They're able to be powered by lipo batteries for on-the-go use or by their micro-USB plugs for stationary projects. Adafruit also offers a line of accessories and Feather Wings to stack boards and add room for prototyping. At its core, the Adafruit Feather is a complete ecosystem of products. View all Adafruit Feather products available at Digi-Key Electronics.