The DS409+ comes in a short, squat case, similar-looking to a Shuttle XPC mini-desktop chassis design, such as the Shuttle SDXi Barebones System; in fact, upon first glance, you might mistake the DS409+ for a mini-desktop PC.
The DS409+ chassis measure 7.25x6.5x9.25-inches (HWD), and is made of black aluminum and plastic with gold highlights. The front panel houses the device's power button and LED status lights. The back of the device includes DC in, Gigabit Ethernet (RJ-45), eSATA, and two USB 2.0 ports.
To open up the unit, you remove four thumbscrews on the back panel, after which the panel pivots down and out of the way on hinges; then you lift up and remove the upper section of the case. The back panel includes two cooling fans. The DS409+ comes with four SATA connection cables of two different lengths, with the longer cable lengths meant to be used with the drive in the top-most bay, and the shorter cables with the drive in the bottom bay.
The four bays are designed to let you slide in 3.5-inch drives--a total of 16 mounting screws are also included. Installing the drives can be time-consuming process, and we wish that the DS409+ instead used a tray-based and tool-less drive installation kit that didn't involve us chasing dropped screws across the floor. You can also use 2.5-inch drives with the DS409+, which require the optional 2.5-inch "Type B" Disk Holder ($9.99 each, direct from Synology). The DS409+ also comes with four SATA power cables.