What this means
The IEEE assigned the MA-L block 4CD73A to ShenZhen XinZhongXin 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 4C:D7:3A, it is ShenZhen XinZhongXin Technology Co.， Ltd hardware.