This is the FeatherWing Quad 2x2 - a prototyping add-on and more for all Feather boards. This is similar to our FeatherWing Proto except there are four! The magic of the Quad comes when you want to connect your Feather to three other Feather Wings without needing any stacking headers. The boards are all set up in a 2x2 grid, thus the name The Quad comes with: