The SC420 is a 2U expansion enclosure that supports up to 24 2.5-inch hard drives installed vertically side by side. An SC420 expansion enclosure ships with two redundant power supply/cooling fan modules and two redundant enclosure management modules (EMMs). Here at The Server Store the customer always comes first. If you have any questions concerning our product please feel free to call or chat with us at any time. Don't forget to check out the rest of our wide array of refurbished IT Equipment here at The Server Store.