EN Technologies Inc.

Any device whose MAC address begins with 00:21:40 has a network interface built by EN Technologies 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

00:21:40

Organization

EN Technologies Inc.

Address

Geumbok Bldg. 9F, Band-yi-dong 45-2, Songpa-gu Seoul KR 138-828

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.