RF-BM-S01 Bluetooth 4.2 module is based on Texas Instruments CC2540 SoC. This BLE module is aimed at the markets with a USB port need and the low power energy need. The high and stable performances make the module be one of your best choices.
RF-BM-S01A module is based on Texas Instruments CC2541 SoC. The higher and more stable performances enable the CC2541 module to enter a wide range of applications. RF-BM-S01A is one of the most classic Bluetooth LE4.2 modules.
As one of the most popular modules, the RF-BM-S02 CC2540 Bluetooth LE4.2 module is designed for battery-powered based applications. The classic package size of RF-star enables this serial interface module to have a bigger market since 2010. RF-BM-S02 will be your good choice for design.
RF-BM-S02I is a CC2540 module with an IPEX connector designed for battery-powered and long range requirement applications. This module with small size may be the most suitable BLE part in your design.