NamJunSa

Any device whose MAC address begins with A4:61:91 has a network interface built by NamJunSa. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

A4:61:91

Organization

NamJunSa

Address

12, Gimhae-daero 2635 beon-gil Gimhae-si Gyeongsangnam-do KR 50932

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.