ECOtality North America

Any device whose MAC address begins with A4:D1:D1 has a network interface built by ECOtality North America. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

A4:D1:D1

Organization

ECOtality North America

Address

430 S 2nd Avenue Phoenix AZ US 85003

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.