Instruction:
The memory module is divided into SD, DDR, DDR2, DDR3 . Please check the following list to know what memory module has been installed in your computer, and what memory module you need to buy. If you don't know which memory module is suitable for your computer, please use the software test to see what memory module your favorite computer needs. (Download a CPU-Z software and decompress it), after running the software, look at the "Maximum Bandwidth" column of the "SPD" option, you will see "PCxx00", as follows: (Memory module DDR, DDR2, and DDR3 are not common to each other, and the sockets are also different, and you can' to insert it in, so as not to damage the memory module and the motherboard, remember!)
PC2100 is DDR 266 memory module
PC2700 is DDR 333 memory module
PC3200 is DDR 400 memory module
PC4200 is DDR2 533 memory module
PC4300 is DDR2 533 memory module
PC5300 is DDR2 667 memory module
PC6400 is DDR2 800 memory module
PC8500 is DDR3 1066 memory module
PC10700 is DDR3 1333 memory module
PC12800 is DDR3 1600 memory module

Specifications:
Product type: 4GB 800MHz DDR2
Memory: 4GB
PIN: 240PIN
Frequency: 800MHz
Suitable: For desktop computer
Suitable: For
Voltage: 1.8V
Bandwidth: PC2-6400
Package size: approx. 15 * 6 * 1 cm/ 5.9 * 2.4 * 0.4 in
Package weight: 26g/ 0.9oz

Package List:
1 * 4GB 800MHz DDR2

Note:

The product can only be used for motherboards and does not support for processors.
If the motherboard is equipped with DDR2 interface and the CPU is suitable for this product is compatible with your device. But if the motherboard is too old, and the motherboard does not support 4G memory, this product is not suitable for your device.