What this means
The IEEE assigned the MA-L block 481F2D to Shenzhen Jie Shi Lian Industrial 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 48:1F:2D, it is Shenzhen Jie Shi Lian Industrial Co.,LTD hardware.