The Bluetooth Device Address (sometimes referred to as a Bluetooth MAC address) is a unique 48-bit identifier assigned to each Bluetooth device by the manufacturer. Bluetooth Addresses are usually displayed as 6 bytes written in hexadecimal and separated by colons (example - 00:11:22:33:FF:EE). They are an essential part of Bluetooth-based protocols. The upper half of a Bluetooth Address (most-significant 24 bits) is the so-called Organizationally Unique Identifier (OUI). It can be used to determine the manufacturer of a device (Bluetooth MAC Address Lookup form). OUI prefixes are assigned by the Institute of Electrical and Electronics Engineers (IEEE). An EUI (Extended Unique Identifier) is generally made from an OUI and thus a Bluetooth Address is also an EUI-48. A device that has a Bluetooth address can also have it own Ethernet MAC address.