Chenbro's RM23512E2-L Server chassis provides 12 hot-swap 3.5" 6Gb/s SAS/SATA hard drive bays with 6Gb/s mini-SAS back plane in an efficient 2U form factor designed for the most storage server applications. The chassis does not come with a pre-installed power supply unit, however, it supports a 2U single or 1+1 Redundant PSU which can be purchased separately.