What this means

The IEEE assigned the MA-L block 50F8AD to Nanjing Qinheng Microelectronics Co., Ltd.. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting 50:F8:AD, it is Nanjing Qinheng Microelectronics Co., Ltd. hardware.