'DDR3' is the type (and must be the same as what your computer has).However, your system will operate at the speed of the slowest memory module. Memory is designed to be backward-compatible, so generally speaking, you can safely add faster memory to a computer that was designed to run slower memory. Here's some relevant information from Crucial on memory speeds (emphasis mine): You could add the 1600 MHz memory for your MacBook Pro even though it's designed for a slower memory (1066 MHz) - it ought to work, but you'd be better off buying from a place that accepts returns.
