By minimizing the length of the inner rail, this HP server rail kit is designed to take advantage of short HP servers. Full sized slide rails can protrude past the rear uprights of shallow racks, which makes it difficult to close the rear door or install accessories.This rail kit allows the HP ProLiant DL20 Gen 10 to be installed into any type of server rack and replaces the HP rail kit that would normally come with the server. Depending on your needs, you can select between our standard depth or short depth rail kit.