What this means
The IEEE assigned the MA-M block ECA7B15 to CHICONY POWER TECHNOLOGY (DONGGUAN) 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 EC:A7:B1:5, it is CHICONY POWER TECHNOLOGY (DONGGUAN) CO,. LTD. hardware.