What this means
The IEEE assigned the MA-L block C07878 to FLEXTRONICS MANUFACTURING(ZHUHAI)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 C0:78:78, it is FLEXTRONICS MANUFACTURING(ZHUHAI)CO.,LTD. hardware.