Patriot Signature DDR2 4GB CL5 677MHz SODIMM (PC2 5300) PSD24G6672S PC2-5300 (667MHz) Data Rate 200-Pin Dual in-line memory module Non-ECC Unbuffered 2 Rank Double-sided module 7.8US Refresh Interval (8192 CYCLES/64MS) 1.8V Power Requirement Auto and self refresh capability PCB height: 1181(mil)