What this means

The IEEE assigned the MA-M block 34B5F3A to Bethlabs(Tianjin)Technology 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 34:B5:F3:A, it is Bethlabs(Tianjin)Technology Co.,Ltd. hardware.