What this means
The IEEE assigned the MA-L block 00165E to Precision I/O. 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 00:16:5E, it is Precision I/O hardware.
Frequently Asked Questions
Who owns MAC prefix 00165E?
00165E is registered to Precision I/O in the IEEE MA-L registry.
What does the MA-L registry type mean?
An MA-L assignment, the IEEE's original OUI format, gives the vendor the first three octets and 16,777,216 device addresses under them. Precision I/O's block covers 16,777,216 addresses.
What devices use 00165E?
Any network device with a MAC address starting 00:16:5E was manufactured by or for Precision I/O.