Name:DDR2 Ram Memory Capacity: 4GB Speed: DDR2 800MHz (PC2 6400) Number of Pins: 240 pins Voltage: DDR2 1.8V Type: Memory Ram Read First The Recognition of XP is around 3GB The Recognition of Win 7 32Bit is around 2.26-4.5GB The Recognition of Win 7 32Bit is around 8-16GB PC2 6400 = DDR2 800MHZ (Compatible with DDR2 667MHZ, DDR2 533MHZ) Note: The appearance of different batches of products is slightly different, which does not affect the use colour:Green Material:PCB size:Length: 13.3CM Package Contents: 1 x RAM Memory Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.