What this means
The IEEE assigned the MA-M block 64FB81E to ChengDu KeChuang LongXin Sci-tech 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 64:FB:81:E, it is ChengDu KeChuang LongXin Sci-tech Co.,Ltd hardware.