4GB 2X2GB Memory RAM for Dell OptiPlex 755 Mini Tower 240pin PC2-5300 667MHz DDR2 DIMM Black Diamond Memory Module Upgrade System Specific Memory - Newegg.com
Dell Optiplex 755 SFF Intel Core 2 DUO 3.16GHz 2GB RAM 160GB HDD Desktop PC | RecycledGoods.com
OFFTEK 512MB Replacement Memory RAM Upgrade for Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor) (DDR2-6400 - Non-ECC) Desktop Memory at Amazon.com
8GB (4GBx2) Team High Performance Memory RAM Upgrade For Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor). The Memory Kit comes with Life Time Warranty. at Amazon.com
Dell OptiPlex 755 MT Intel Core 2 Duo E8200 2.66GHz CPU 1GB RAM No HDD
4GB Kit 2 X 2GB DDR2 Memory for Dell Optiplex 755 760 GX280 Ultra Small Form Factor Desktop PC2-6400 240 pin 800MHz Non-ECC DIMM RAM (PARTS-QUICK Brand) at Amazon.com