MICROUNITY SYSTEMS ENGINEERING

Any device whose MAC address begins with 00:40:A3 has a network interface built by MICROUNITY SYSTEMS ENGINEERING. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:40:A3

Organization

MICROUNITY SYSTEMS ENGINEERING

Address

255 CASPIAN DRIVE SUNNYVALE CA US 94089-1015

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.