The KH2508A and KH2516A KVM Switches are control units that allow IT administrators to access and control multiple computers from two PS/2 or USB KVM consoles (one bus). Operators working at up to two consoles can independently and simultaneously take control of up to 8 (KH2508A), or 16(KH2516A),computers. By daisy chaining up to 31 additional switches,as many 512 computer can be controlled from the original KVM consoles.