Seagate ST91000642NS Constellation.2 1TB 2.5" HDDEnsure Data Integrity with Enterprise Class Storage Introducing the Seagate Constellation. 2 ST91000642NS, a robust 2. 5 inch internal hard drive designed for enterprise environments. With its high capacity and reliable performance, this drive is ideal for critical data storage. Specifications: Brand: Seagate Model: ST91000642NS Capacity: 1 TB Form Factor: 2. 5" Interface: 6G SED SATA Speed: 7. 2K RPM