Samsung 4GB 4 x 1GB PC2-4200U DDR2 533 MHz NonECC Unbuffered Desktop Memory Kit Brand: Samsung M378T2953CZ3-CD5 Type: 240-Pin DDR2 SDRAM Capacity: 4GB 4 x 1GB Speed: DDR2 533 (PC2 4200) Timing: 4-4-4-12