Miller Electric Mfg. Co.

Any device whose MAC address begins with 28:A5:74 has a network interface built by Miller Electric Mfg. Co.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

28:A5:74

Organization

Miller Electric Mfg. Co.

Address

N676 Communication Drive Appleton WI US 54914

Source

IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.