What this means

The IEEE assigned the MA-M block 58C41E4 to BEIJING FIBRLINK COMMUNICATIONS 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 58:C4:1E:4, it is BEIJING FIBRLINK COMMUNICATIONS CO.,LTD. hardware.