You can program the CC BEC Pro using Castle Link or Field Link (sold separately).
Castle Creations Battery Eliminator Circuits (BECs) are small devices that eliminate the need for a receiver and servo battery pack. They draw higher voltage from the motor batteries and drop it to a voltage level that is suitable for your receiver and servos. This is required in applications which draw high power for multiple servos or use more than 3S motor packs, as most ESCs with linear BECs are not designed for these applications.