Enter MAC Address To Lookup
How's this work?
The first 6 digits of a MAC address always uniquely reference the hardware's manufacturer. Regardless if you put the full MAC address in, the program will automatically search based on the first 6 since the last 6 only uniquely identify the card. That being said, this then does a lookup against the MAC address listings published by IEEE, which can be found here.

Database last updated: March 18, 2013