As a global leader in the PC market, IBM develops, manufactures and markets cutting-edge, reliable, high-quality PC products and value-added professional services that provide customers around the world with smarter ways to be productive and competitive.This feature provides the licensing and support for attaching a third EXP810/7xx Expansion Unit providing DS4300 support for up to 62 DS4000 Disk Drive Modules. This feature is only applicable if feature #2011, Model 6LU Upgrade has been ordered.