Web Sensing LLC

Any device whose MAC address begins with 34:0F:66 has a network interface built by Web Sensing LLC. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

34:0F:66

Organization

Web Sensing LLC

Address

P.O. Box 692 Hanover NH US 03755

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.