661-5031 13inch Macbook 2GHz, Memory, 1GB, SO-DIMM SDRAM, DDR2 667, Early 2009 NB-1838W
This is a 1GB DDR2 PC5300 SODIMM for many models of the Macbook, Macbook Pro, Mac Mini, iMac, etc..
Apple part number: 661-5031
Compatible models: White-A1181, MB881LL/A,
Compatible Mac info. : 2.0GHz Core 2 Duo 13-inch Macbook
661-5031 13inch Macbook 2GHz, Memory, 1GB, SO-DIMM SDRAM, DDR2 667, Early 2009