This is a left speaker assembly for the 13" Macbook (Black and White models only). There are two styles of cables on the MacBook: the 3-wall and the 4-wall cable. Looking at the end connector, the 4-wall looks like a standard plug-in type socket connector with four sides around the port and was typically used on the older Core Duo models. The newer 3-wall style looks like it would slide into the port as the connector on the board is open on one side and was used on most Core 2 Duo models. **Note** Some early Core 2 Duo models used the 4-wall connector, so please look at your old cables before ordering this part unless you are sure.