Pi-Top Proto ACPRGR100000
This board allows you to connect to the GPIO bus on the Raspberry Pi that is installed within your Pi-Top Laptop or Pi-Top Ceed. The prototype board slides into position on the rail and plugs into the connector on the left side. You can chain accessory boards together on the rail.
You can connect a standard 40-pin GPIO cable to the card allowing you to connect an external breadboard, or access many of the GPIO signal pins from the card itself allowing you to quickly prototype a circuit directly within the Pi-Top itself without the need for an external breadboard. HINT: If you plan on connecting a standard 40-pin GPIO cable to the board to bring the GPIO outside the Pi-Top unit, you should get a 24" (or longer) GPIO cable.