The memory I have installed in my recently purchased MacBook Pro 13 "(Model Mid 2012). The modules are designed for 1.5V voltage, which is not a problem as the original built-in modules (2x2GB) were also 1.5V modules. The 16GB will automatically detect (MacOS Mavericks and Windows 7), under MacOS are 1024MB reserved for the graphics card (with 4GB there were I think 256MB). The system is so far free of errors and corresponding applications much smoother.