Typically, the Phantom Specter system consists of two separate units: one Universal Phantom Specter Manager unit (item #27452, not included), and one Phantom Specter II remote unit per computer (not included) for up to 63 servers per line. For the remote unit, you can choose per your platform environment - PS/2 (item #27453), Sun(R) (item #27454), RS-232 (item #27455), or USB/Sun USB (item #27460). However, to add multi-user capability, you also need to add this Specter MX II Manager. Now two Phantom users can simultaneously control and manage up to 63 servers - an ideal solution for larger data centers that require more than one supervisor, and need the flexibility of operating from both local and remote locations.This micro-sized KVM switch is especially designed for single user KVM management for up to 63 servers on a single line; it's the ideal solution for high density server and rack environments including server farms, data centers or corporate server rooms. Enjoy flexible server/KVM console placement up to 110 meters (360 feet) away. The micro-sized Specter provides much more power than a conventional switch while freeing up rack space, eliminating cable clutter and maximizing your flexibility. Note: no external power supply at the Specter units.This is a pure hardware solution (BIOS level access) that uses low density Cat5 cabling, and is scaleable - buy only what you need and add as you grow. It features advanced On Screen Display (OSD) management, including multi-layered security, the most efficient way for monitoring, accessing and controlling your servers. Plus, you can manage your Phantom system, via a serial port, using the Phantom's control software or any other third party software.The Phantom's Distributed Switching Technology (DST) divides the KVM switch into smaller subunits: two Managers and multiple Remote units. The Remote units can be placed inside the servers (PCI cards) or on the side or back of the rack (Specter Units) where they occupy no rack space! Now you can dedicate more of your rack to servers instead of wasting space on switches. Not sure what resolution you need? See our VGA resolution guide.