Install SQL Server 2008 R2 10.50.1600.1 or 10.50.4000.0?

I'm building a new farm and need to install SQL server. I have SQLServer2008R2SP1-KB2528583-x64-ENU.exe on the network, but I'm not sure if this isonly SP1 or the full version of SQL Server 2008 R2 with SP1.

Once SQL is installed, I'll need it to match another server at SP2, 10.50.4000.0. Is there an SQL Server 2008 R2with SP2?

Thanks,

Scott