EMSTONE

Any device whose MAC address begins with F4:49:EF has a network interface built by EMSTONE. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

F4:49:EF

Organization

EMSTONE

Address

#1201, Byeoksan Digital Valley 3rd, 271, Digital-ro Guro-Gu Seoul KR 08381

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.