OFFTEK 512MB Replacement Memory RAM Upgrade for Dell OptiPlex GX620 Series (Desktop Mini-Tower and Small Form Factor) (DDR2-4200 - Non-ECC) Desktop Memory at Amazon.com
Dell OptiPlex GX620 USFF Intel Pentium D 3.0GHz 2GB RAM, DVD-RW, No HD – Hung Tran
Dell Optiplex GX620 MT Intel Pentium D 3.0GHz CPU 2GB RAM No HDD No OS | eBay