Crucial CT25664AA800 4GB 2 x 2GB PC2-6400U DDR2 800 Non-ECC Unbuff Memory Kit Brand: Crucial CT25664AA800.K16F Memory Type: 240-Pin DDR2 SDRAM Capacity: 4GB 2 x 2GB Speed: DDR2 800 (PC2 6400) Cas Latency: 6