What this means
The IEEE assigned the MA-M block C0FBF9C to SHENZHEN ELSKY 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 C0:FB:F9:C, it is SHENZHEN ELSKY TECHNOLOGY CO., LTD hardware.