4 port USB KVM switch which allows the user to control 4 PCs with only 1 USB keyboard 1 monitor and 1 USB mouse. The KVM switch is operating system independent so it will work on Windows Mac OS and Linux (please note the software only works on Windows). The KVM can be controlled by either using the hotkey function on the keyboard the push buttons on the KVM unit itself or depending on operating system the software provided Specification 4 Port KVM Switch Max Resolution: 2048 x 1536 Supports Auto-Scan Function Has speaker & microphone port Push button & hot-key switch function OS independent (software only works in Windows)