Smartronix, Inc.

Any device whose MAC address begins with 00:05:20 has a network interface built by Smartronix, Inc.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:05:20

Organization

Smartronix, Inc.

Address

22685 Three Notch Rd. California MD US 20619

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.