Full Details from Amazon.com : http://www.amazon.com/gp/product/B007HAXTHW?tag=onigi-20

2GB Upgrade for a Dell Inspiron 1720 System (DDR2 PC2-6400 NON-ECC )

200-pin SODIMM
DDR2-800
DDR2 PC2-6400 Unbuffered NON-ECC DDR2-800 18V 256Meg x 64
The only brand of memory upgrade available directly from a DRAM manufacturer tested to meet the most stringent industry specifications
Install it yourself in about 15 minutes The same top-quality memory that the worlds largest computer manufacturers install in the systems they sell