Sercomm Japan Corporation

Any device whose MAC address begins with 18:EF:C0 has a network interface built by Sercomm Japan Corporation. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

18:EF:C0

Organization

Sercomm Japan Corporation

Address

8F, 3-1, YuanQu St., NanKang, Taipei 115, Taiwan Taipei TW 115

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.