Double Raid! Two 3.5" HDDs fit into this enclosure and can be used in RAID modes 0, 1, JBOD (Large) / Nor (SINGLE) and one 2.5" HDD or SSD can be installed and used as an extra but it’s not part of the raid network. Better safe than sorry The enclosure is made entirely of metal and the hard disks are provided with a lock that prevents accidental opening and unauthorized access. An LED also indicates operation and disk access for each storage medium. When it’s hot The aluminum dissipates heat very well and the cooling of the drives during heavy operation is ensured by a 60 mm fan on the back. An alarm warns of excessive temperatures or fan failure via LED and sound.