What this means
The IEEE assigned the MA-M block 98AAFC8 to Beijing Tiandi-Marco Electro-Hydraulic Control System Company 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 98:AA:FC:8, it is Beijing Tiandi-Marco Electro-Hydraulic Control System Company Ltd. hardware.