The Terminal Block Breakout FeatherWing kit is like the Golden Eagle of prototyping FeatherWings (eg. majestic, powerful, good-looking). To start, you get a nice prototyping area underneath your Feather, with extra pads for ground, 3.3V and SDA/SCL. Not one to stop there, we expanded the PCB out to 2" x 2.5" with 3.5mm pitch terminal blocks down each side. There's also four mounting holes so you can attach the breakout to your enclosure or project.