Secure Letter Inc.

Any device whose MAC address begins with 38:14:1B has a network interface built by Secure Letter 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

38:14:1B

Organization

Secure Letter Inc.

Address

223, Yeoksam-ro Gangnam-gu Seoul KR 06224

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.