the difference between USB-CAN adapter (two extra boards) and USB-CAN Interface

Here is one video demo for automotive CAN message capturing.    http://www.viewtool.com/index.php/en/27-2016-07-29-02-13-53/44-ginkgo-usb-can-9 CAN adapter (A) and CAN interface (B) are both CAN standard protocol functional, The difference is: 1. Performance (speed): B is better than A, as B is working with a higher performance ST MCU (as CAN hardware);  2. Isoloation: B is 2500V isolated (all signals and power supply, GND between CAN bus and MCU+USB), so that's capable to be used in industry environment in term of interference and power surge, etc;  3. GPIO: A could use many GPIO as well as ADC (20 pins lead out, multiple functional) simultaneously working with CAN protocol. see one example :     http://www.viewtool.com/forum/forum.php?mod=viewthread&tid=169&extra=page%3D1 And plus: A could be turned to I2C or SPI adapter by burning specific firmware (see website for more detail);  B is only be used for CAN protocol (2 channels same as A);  4. Accessories: A has accessories same as ViewTool Ginkgo I2C adapter (and SPI adapter), because it could be turned to I2C or SPI adapter, and additional two CAN driver modules included.  5. Price: A is around 20% cheaper than B;    详情：http://www.viewtool.com/forum/forum.php?mod=viewthread&tid=170&extra=page%3D1