QNAP 4-bay 1U iSCSI NAS, Hot-swappable, Marvell 1.6GHz CPU, 1GB RAM, USB3.0. The QNAP TS-420U Turbo NAS is an all-in-one rack mount network attached storage (NAS) server optimized for small and medium businesses looking for an affordable yet high performance network storage solution. The TS-420U can hold up to 4 hard drives and is designed to be easily installed in the server room and configured with up to 12TB of storage capacity. The TS-420U is an ideal solution for centralized data backup, cross-platform file sharing, iSCSI/IP-SAN storage combo solution and a number of business applications. Moreover, the TS-420U offers exceptionally low power consumption, reliable system operations and capacity expandability. Does Not Include HDDs.