Each memory through the various types of manual testing, make the product can used in different application environments,be to provide users with both high-per compatiblemance and high stability of the computer experience. Whether it is general user, gamers, or computer enthusiasts, can feel memory bring the per compatiblemance improvement compatible computer Hard disk/flash memory vendors are using decimal arithmetic: 1MB=1000KB, 1G=1000MB calculated, but the is using binary arithmetic: 1MB=1024KB, 1GB=1024MB. So there are some differences between display capacity and nominal capacity of hard disk/flash memory products. However, this is allowed to exist. Please do not doubt his authenticity. Specification: Type: DDR3 Capacity: 4G Frequency: 1600MHz Working voltage: 1.35V Memory Channel: Dual Channel Pins:240pins Unbuffered, Non-ECC, & Non-Registered Colour: blue Material: PCB Size: 13.3x3cm Package Contents: 1 * DDR3 4GB Desktop Memory Ram 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.