OPTO-22

Any device whose MAC address begins with 00:A0:3D has a network interface built by OPTO-22. 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:A0:3D

Organization

OPTO-22

Address

43044 BUSINESS PARK DR. TEMECULA CA US 92590

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.