Sun products are designed for seamless integration into various environments. They are scalable solutions optimized for critical tasks. Be assured that Sun products represent the latest developments in computer industry to give you more power and strength.This product is Sun StorEdge L8500 Expansion module that holds additional 1728 slots, taking the L8500 from 1448 to 3176 total slots. Either this or SG-XL8500-1EXM-NR is required for configurations of 1750 slots and greater. Number of slots accessible is based on cartridge slot expansions purchased. Includes new rails that the robots travel on. Installation included. RoHS-5.