661-5595 DDR3 1066, SO-DIMM - SDRAM, 4 GB - 13inch 2.4-2.66GHz Macbook Pro A1278 Mid 2010 NB-4139W
This is a 4GB Ram upgrade for various Mac models. THIS IS A SINGLE CHIP, NOT TWO CHIPS. Specs: 4GB DDR3 PC3-8500 SODIMM.
Apple part number: 661-5595
Compatible models: Unibody-A1278, Unibody-A1278, MC374LL/A, MC375LL/A,
Compatible Mac info. : 2.4GHz Core 2 Duo 13-inch 2.66GHz Core 2 Duo 13-inch Macbook Pro
661-5595 DDR3 1066, SO-DIMM - SDRAM, 4 GB - 13inch 2.4-2.66GHz Macbook Pro A1278 Mid 2010