This is a bluetooth cable for the Macbook 13". This cable runs from the Bluetooth board to the logic board.
There are two different types of connections, a 4-wall connection and a 3-wall connection. The Core Duo systems and early Core 2 Duo models used a 4-wall connection, while later Core 2 Duo models used a 3-wall connection. Please be sure to check compatibility with your machine before purchasing.