It is Bluetooth 2.0 Module+PIC18F25K80 Chip Hardware V1.5,please check Real PCB Board(1PCB Board on Main Unit): 1PCB Board MAC Address will be Random Hardware V1.5, it is more stable and supports more cars than ELM V2.1. Hardware V1.5 is More Powerful than V2.1. Hardware V1.5 Suppo...