This is an ATEN 16-port KVM switch built in an ultra-short-depth, single-rail chassis — a compact rack-mount design that fits in racks or cabinets too shallow for a standard-depth KVM console, while still switching PS/2 and USB keyboard/mouse plus VGA video across all 16 connected servers. The "single rail" mounting means it uses one set of rack rails rather than the deeper telescoping slide rails a full LCD-drawer console needs, trading the built-in monitor/keyboard drawer of other ATEN models in this catalog for a smaller footprint — this unit is a pure switch, intended to be paired with a separate monitor/keyboard rather than housing its own.