What this means
The IEEE assigned the MA-M block 24A3F0C to BEIJING CUNYIN CHENGQI 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 24:A3:F0:C, it is BEIJING CUNYIN CHENGQI TECHNOLOGY CO., LTD. hardware.