Abstract: A novel tray assembly for a rack mount type storage unit is provided. The tray assembly is adapted to receive an enclosure. When within the tray assembly, the enclosure may be located within a first position, a second position or a third position. When in the first position, the enclosure is fully received within the tray assembly and the tray assembly is fully received within the rack and is operational. When in the second position, the tray assembly is fully received within the rack and the enclosure is partially slid out of the tray assembly and rack for maintenance, repair, etc. while the enclosure is still powered and running. When in the third position, the enclosure is fully received within the tray assembly for easy insertion into or removal from a rack.