RAM & Memory Upgrades
6GB (4GB + 2GB) DDR2 800MHz PC2-6400 200-PIN SODIMM MEMORY RAM KIT COMPATIBLE WITH INTEL MACBOOK 13 INCH (2.13GHz) (MID 2009)
SIZE/CAPACITY: 6GB KIT (4GB + 2GB) VOLTAGE/POWER CONSUMPTION: 1.8v CAS LATENCY: CL6 SPEED: PC2-6400 (800MHz) TYPE/INTERFACE: 200-PIN DDR2 SODIMM 200-PIN MACBOOK & MACBOOK PRO DDR2 SODIMM
https://www.bizrate.co.uk/ram_memoryupgrades/6gb-4gb-2gb-ddr2-800mhz-oid36970010701.html