What this means
The IEEE assigned the MA-S block 70B3D57F3 to Shenzhen Virtual Clusters Information 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 70:B3:D5:7F:3, it is Shenzhen Virtual Clusters Information Technology Co.,Ltd. hardware.