This is a SAS hard drive and is not a standard SATA desktop drive. It requires a compatible SAS RAID controller, server backplane, disk shelf, or enterprise storage enclosure; a normal SATA-only motherboard connection will not operate this drive. The exact ST12000NM0158 / 0YMN53 / 2H3231-150 identifiers can be important when replacing an existing Dell EMC drive, so please compare the label and part numbers with your current hardware before ordering. Unit is used and may show normal cosmetic wear from prior installation and storage. Buyer receives one bare hard drive per purchase; no caddy/tray, SAS cable, mounting hardware, or other accessories are included unless specifically shown in the photos.