The Bitcraze BigQuad Deck enables the transformation of the Crazyflie 2.X into a larger quadcopter by facilitating the connection of external Electronic Speed Controllers through its breakout connectors. This deck supports the integration of additional accessories, including an external receiver and GPS, enhancing the functionality of the quadcopter. It also features the capability to monitor battery voltage and current, ensuring efficient power management. The deck's design allows for the automatic detection of expansions, streamlining the upgrade process.