Shenzhen ACT Industrial Co.,Ltd.

Any device whose MAC address begins with E4:81:B3 has a network interface built by Shenzhen ACT Industrial Co.,Ltd.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

E4:81:B3

Organization

Shenzhen ACT Industrial Co.,Ltd.

Address

NO.5 B/D,BEISHAN INDUSTRIAL PARK,BEISHAN R/D, Shenzhen Guangdong CN 518083

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.