What this means
The IEEE assigned the MA-M block 8C5570D to EPSa Elektronik & Präzisionsbau Saalfeld GmbH. 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 8C:55:70:D, it is EPSa Elektronik & Präzisionsbau Saalfeld GmbH hardware.