Each of the modules has the STM32F103 microcontroller, the CW1100 and an internal voltage regulator. The module only requires 3.3 V and it does not need anything else. On the CW1100, there is an integrated power amplifier as well as onboard crystals at 38 MHz. That is on the SPWF01SA and SC.21 series. The SA indicates that there is an integrated antenna, the SC indicates that there is a U.FL connector for an external antenna. On the datasheets, there is one approved FCC external antenna dongle that the customer can use and still keep full FCC compliance with the module. When designers test with FCC, they have to have the full antenna package together and tested, so ST has certified one antenna dongle that is available from distribution that customers can use when the module has to be placed somewhere where an external antenna is required. On the F103, there's access to 16 GPIOs. They can be configured as general purpose input/outputs, PWMs, ADCs, and DACs. On the 11 series, there is 1 MB of additional flash to the 512K flash that's on the F103. That 1 MB of flash allows for flash file systems that users can load onto the module and firmware over-the-air updates. The dimensions of the module are 26.92 x 15.24 mm which means it is relatively small in size, but fully integrated with the antenna or the U.FL connector.