Must be installed in Matched Pairs. 4GBx2 .

8GB Total. Uses a very reliable micron chip.

Compatible with MacBook Late 2008, Mid 2009, Mid 2010; Mac Book Pro Late 2008, Early 2009, Mid 2009, Mid 2010, Early 2011; Mac Mini Early 2009, Late 2009, Mid 2010; iMac Intel Early 2009, Mid 2010, Mid 2011.

Although the memory specification for the following models is PC3-8500 1066MHz, but this PC3-10600 1333MHz memory is 100% compatible，and works at 1066MHz with better margins.
MacBook Pro Late 2008-Mid 2010，iMac Early 2009/Late 2009, Mac mini Early 2009-Mid 2010，MacBook Late 2008 and Late 2009-Mid 2010