Although these Memory modules are not IBM Originals we guarantee them to work and meet the specifications of the IBM Part Numbers below: IBM PART# 31P8857 Compatible 1GB PC2700 DDR Memory Kit $140.00 IBM PART# 22P9272 Compatible 1GB PC3200 DDR DIMM $148.00 IBM PART# 31P8856 Compatible 512MB PC2700 DDR Memory Kit $52.00 IBM PART# 73P2686 Compatible 512MB PC3200 DDR Memory Kit $55.00 IBM PART# 31P8855 Compatible 256MB PC2700 DDR Memory Kit $27.00 IBM PART# 73P2685 Compatible 256MB PC3200 DDR Memory Kit $29.00 IBM PART# 73P5121 Compatible 2GB PC3200 DDR DIMM KIT $250.00 IBM PART# 73P5122 Compatible 4GB PC3200 DDR DIMM KIT $850.00 IBM PART# 30R5086 Compatible 512MB PC2100 DDR DIMM $75.00